Department of Communication Arts
	Research	Links	Streaming Examples

Contents • Chapter 1 • Chapter 2 • Chapter 3 • Chapter 4 • Chapter 5 • References

CHAPTER II

REVIEW OF THE LITERATURE

Introduction

            A review of the literature related to streaming video in education was conducted, and is presented as follows: (a) overview of streaming video technologies, (b) streaming video research, (c) overview of streaming video practices, (d) research on the effectiveness of Web-based instruction, (e) research on the effectiveness of video in non-streaming media applications, such as videotape, and (f) factors that impact the usability of streaming video. The review of the literature included on-line Internet resources and research articles, books, journals, interviews, and microfiche documents.

Overview of Streaming Video Technologies

Streaming video is transmitted over a data network. The term implies a one-way

transmission to the viewer, in which both the client and server software cooperate for uninterrupted motion. The client side buffers a few seconds of video data before it starts sending it to the screen, which compensates for momentary delays in packet delivery.

With non-streaming video, a significant portion of the video file must be successfully downloaded over the Internet before a video clip can begin playing. Streaming video allows for live video transmission over the Internet, and it allows the server to dynamically adjust the video data transmission rate depending on the user’s current connection status, whether that connection is a high-speed T-1 line or a 56K dial-up modem (Dixon, 2000).

The ability to play video over the Internet is recent. Just five years ago, the only way to play video on a computer was to completely download a video file from an Internet server or play it from a CD-ROM on the local computer. In the days before the widespread use of high-speed modems, video files would take a very long time to download, and the files had to completely download before playback would be possible. The compression technology was primitive and video quality was extremely poor. Video played from CD-ROM drives was often jerky, low quality, and usually described as “postage-stamp” video due to its small size (Rule, 1999). Computer and video compression technology have advanced to the point where it is now possible to play video over Internet connections in real time and with much higher quality. Although streaming video is far short of broadcast television standards, it is now considered an acceptable delivery medium for a wide variety of uses (Pescatore, 2000).

Compared with most types of data, video files are very large. Uncompressed video, such as that found inside a television production studio, is composed of thirty individual and unique frames per second. Each frame has a resolution of 720 x 486 pixels, which requires almost 170 million bits per second to transmit. This is much too high a data rate for most computers to handle, so the video file must be compressed to be usable and manageable (Strachan, 1996). A video file that is accessed via the Internet must be very heavily compressed. Often, the frame rate per second is sharply reduced and the resolution is decreased to a quarter of its normal size (Bress, 2000). This large amount of compression is possible because the human visual system can still make sense of a video sequence that has been compressed enough to either be downloaded or streamed over the Internet (Strachan, 1996).

Overview of Methods for Streaming Video

There are two ways to play a video file obtained from the Internet. The first is to download the entire file to a storage device such as a hard drive before playback can commence. This is the method originally used on the Internet, and because most video files are at least 1MB in size or larger even after being compressed, downloading the entire file is not an efficient way to handle video on the Internet (see Table 1). For example, a 45-second video clip with a resolution of 160 x 120 pixels is about 1.5MB, which can take a considerable amount of time to completely download over a modem (Dixon, 2000).

To overcome this limitation, a technology called progressive download was developed which allows the video file to begin playing before the entire file has been downloaded. Although video files played back using progressive download appear to stream, this is not actually the case. The user’s computer simply begins playing the clip when it guesses that enough of the file has been downloaded to allow uninterrupted playback. The clip does not therefore begin playing immediately, and if the computer has guessed wrong, or the Internet connection slows down, the video clip could freeze. One advantage of progressive download is higher video quality, because streaming video requires considerably more compression to ensure continuous playback (Simpson, n.d.).

Downloading video files, either via straight download or progressive download, makes use of the Hypertext Transfer Protocol (HTTP). This is the same data transfer protocol that Web page text and image data use. HTTP was designed to maximize the data transfer rate of the entire network. Under HTTP, video files do not have priority over text data, which could cause the video data transfer rate to drop tremendously if another user suddenly requests a Web page. HTTP does check to make sure that all of the data has reached its destination, so that one can be sure that the entire file has arrived. The factors just mentioned make HTTP file transfer ideal for situations where receiving the entire file is critical, but present a problem for live video transmission. In live video transmission, continuous real-time playback is essential. Dropped or missing bits of data are considered of secondary importance, which is incorporated in the design of streaming video protocols (Windows Media, 2000a).

The second playback method is to stream the video so the user can view the video clip as the data arrives at the computer. Streaming video can be compared to broadcasting a file from a server to a remote computer. When a signal is broadcast, it is sent from a broadcaster to a receiver in real time, with no or very little provision for retransmission. Likewise, when a video clip is streamed, the server sends the video data over the Internet to a remote computer in real time, and if any data are lost during the transmission process, that data are gone forever. The streaming video player software on the remote computer simply ignores it and continues to decode and playback the rest of the incoming data. Unlike a video clip that is being downloaded, a streaming video clip begins playback immediately, without waiting for a significant portion of the file to download. This allows transmission of live video data over the Internet. Streaming video clips are of lower quality than clips that are downloaded. When a clip is downloaded and then played, the user’s computer and the server negotiate to ensure that the entire clip is successfully downloaded, which allows the downloaded clip to be of whatever level of quality the creator of the clip desires. A clip that is streamed, however, has to be of considerably lower quality due to the incredibly high compression required to allow real time playback over a modem connection. Additionally, streaming video will skip over any lost data, which can cause jerky movement in the clip, whereas a downloaded clip can go back and reload any lost or missing data (Griffin, 1998).

Streaming video makes use of specialized data transmission protocols with the purpose of ensuring that video data packets arrive as quickly as possible at the user’s computer. Typically, these protocols skip over dropped, lost, or slow video data packets instead of waiting for them to arrive or requesting a re-transmission because continuous playback is the priority (Simpson, n.d.). An additional benefit to these protocols is the ability to transmit video data for the same clip from differently compressed files. This lets users with dial-up modem connections of less than 56 kilobits per second receive a video stream. If a user with a faster Internet connection such as a DSL or cable modem connection accesses the file, that user will receive a higher video quality stream. This is accomplished by encoding various versions of one clip targeted at different data rates, and then letting the server decide which version to stream to the user (Simpson, n.d.). RealNetworks developed the Real Time Streaming Protocol (RTSP) that gives the server the ability to adjust data rates in real time to compensate for changing network transmission conditions. This capability allows a video clip to play smoothly, usually giving priority to audio playback when network data rates drop, or increasing the video data rate under favorable network conditions (RealNetworks, 1998 a). The second specialized protocol for streaming video is the User Datagram Protocol (UDP). Microsoft Windows Media Player uses UDP. This protocol does not have a provision for data retransmission when video data packets are lost, nor does it have a data rate management capability. UDP does give video data higher priority than regular HTTP data, which helps maintain continuous video playback. The latest versions of Windows Media Server use a slightly modified version of UDP, which allows retransmission of certain video data packets that the server determines will not interfere with smooth playback of video. Microsoft incorporated this to increase video playback quality (Windows Media, 2000 a).

Overview of Streaming Video Software

There are currently three main software formats to choose from when streaming video over the Internet. Over 125 million Internet users, with over 175,000 new users every day, reportedly use the first of the three, RealNetwork’s RealVideo 8. RealVideo 8 supports live video streaming, on-demand streaming of video clips, and streaming of PowerPoint-like presentations called RealSlideshows. RealVideo8 is also being bundled with new Gateway and IBM personal computers, as well as new America Online accounts (RealVideo, n.d.). The basic software player version of RealVideo 8 can be downloaded free, with an enhanced version offering more video display and control choices for $29.99. The server software, required to stream videos over the Internet, is licensed according to the number of simultaneous video streams the Web site can provide. RealServer Basic supports 25 simultaneous streams at no charge. If the capability of more simultaneous streams is required, RealNetworks quickly becomes the most expensive of the three formats, starting at nearly $3,000 for 60 simultaneous streams of video with the RealServer Plus, and going up to over $50,000 for the Professional Broadcasting Solution capable of 400 simultaneous video streams (RealNetworks.com, n.d.).

Microsoft’s Windows Media Technologies 7 is an alternative to RealNetwork’s products. The newest of the three formats, Microsoft claims that Windows Media Player 7 is quickly becoming the streaming system of choice on the Internet. Windows Media Player 7 claims to provide higher quality video than any other format, as well as audio clips that are half of the file size of the popular MP3 format, but with the same quality. Microsoft does not charge a license fee for the player or server software, in direct contrast to RealNetwork’s pricing formula. The streaming server software is bundled with Windows 2000 Server, Microsoft’s Web server package, and simultaneous streams are unlimited. The actual Windows 2000 Server software starts at $1200 for the basic server package, and increases in price based on the number of client computers allowed access. This client computer model does not count Internet browsers as client computers (Windows Media, 2000b).

Apple’s QuickTime 4.0 is the third major format for streaming video with over 100 million downloads of QuickTime 4.0 (QuickTime, n.d.). QuickTime, the oldest digital video architecture, originally did not support true streaming. Early versions were download-only, and progressive download became available with version 3.0 (Waggoner, 2000). Like RealNetworks and Microsoft, Apple offers a free version of the QuickTime player, with an enhanced version, which allows recording and editing available for a small fee. QuickTime Streaming Server is included at no charge with Mac OS X Server and supports over 2000 simultaneous streams. QuickTime Streaming Server is only available for Macintosh servers, however (QuickTime Streaming Server, n.d.).

Streaming Video Research

A considerable body of literature exists on the subject of current and potential uses of streaming video, but only one study was found that actually incorporates streaming video in a research design. Hecht & Klass (1999) examined whether or not streaming audio and video technology could be used for primary instruction in off-campus research classes. The study was conducted using two graduate level research classes in the College of Education at Illinois State University beginning in the summer of 1998. Various methods of distance education including compressed video over dedicated lines and over the Internet were considered before the authors settled on a streaming video solution.

A master’s level qualitative research in education course delivered simultaneously to both an on-campus and an off-campus cohort comprised the first trial. Both cohorts consisted of 20 graduate students. The off-campus cohort consisted of 20 students enrolled in a doctoral program administered by Illinois State University to educators in Thailand. Previously, instructors traveled to Thailand to deliver courses in person over a four-week period. The authors felt that the four-week period was too short for the students to adequately learn the intended course content. Using Real Media’s streaming technology, the qualitative research class was offered to the off-campus cohort in both synchronous and asynchronous modes. The on-campus cohort attended the class at the regularly scheduled time with the instructor. For each class meeting, the course was streamed in real time from a distance education classroom containing cameras, microphones, and other multi-media equipment. Students in the off-campus cohort had the option of participating in the class synchronously over the Internet, or of participating asynchronously over the Internet using archived streaming video. Various tests of data rates, audio and video compression schemes, and connection strategies were performed prior to the beginning of the class. It was determined that no one setting would be ideal. The instructor thus had to be willing and able to change software settings during a class session. Classes were transmitted live at a rate requiring off-campus students to have a high-speed Internet connection. Taped classes were encoded and available at two different data rates, one for students with high-speed Internet connections and one for low-speed dial up modem access with preference given to audio in the streaming process. Few problems were reported with the hardware and software over the course of the 14-class sessions. A number of important observations can be gleaned from the student comments about the course. One on-campus student stated, “It felt, at times, like [the instructor] was teaching two different classes at once.” This was explained as being a function of the real-time chat provided for off-campus students participating synchronously in the course. The interactive chat system allowed off-campus students to communicate among themselves, and to question the instructor. However, the chat system did not permit instantaneous interaction between the instructor and student. Slow response times made it seem to the off-campus students that by the time the instructor would receive a question, the instructor would already be well into another topic. The flexibility of being able to participate in the class either synchronously or asynchronously was appreciated by many of the off-campus students. A few of the off-campus students did report not liking the delivery of this course by streaming video at all, preferring instead an asynchronous course without taped or live streaming lectures. The instructor reported having to spend large amounts of time to tailor the course to what amounted to three different modes of delivery: live and in-person, live and at a distance, and asynchronous. No results on student achievement or learning were reported.

The second trial in the study used a doctoral-level research design and statistics class. The second trial was further broken down into two sections: a section reserved for a cohort of 25 students from the university’s Thailand doctoral program, and a cohort of 14 doctoral from an off-campus site three hours from Illinois State University. The Thailand cohort would participate in the course using the same methodology from the first trial, either synchronously or asynchronously depending on preference using Real Media’s streaming video technology. The section of off-campus students not living in Thailand was to be provided a choice of point-to-point interactive compressed video or the streaming video method the overseas cohort used. However, the interactive compressed video system did not become operational; therefore, the non-overseas cohort was limited to the streaming video delivery method. The authors report that this was unacceptable as the only delivery method to students in that cohort, so the instructor agreed to teach the non-overseas group in person. The streaming video material was used when students could not attend the live class. More Internet-related connection problems were reported for this course. A number of students had problems with Internet congestion, and others, with the minimal hardware configuration recommended by Real Media, experienced losses of video or audio while attempting to participate in class. Several instructor issues are noteworthy. The instructor reported that because of the time required for the creation and maintenance of the class, the tendency was to rely heavily on the streaming lecture rather than on activities and content geared to on-line delivery. Additionally, the instructor felt that offering course content using a wide variety of delivery methods, including video lectures, PowerPoint slide shows, on-line chats, and threaded discussion lists, may have overwhelmed the students. The impacts of streaming video on student achievement were not reported.

A difference in attitude between the Thai cohort and the non-overseas cohort was observed, however. The Thai cohort felt that the Internet extended opportunities for more interaction within the course. The non-overseas cohort felt that the streaming video delivery was a major imposition (Hecht & Klass, 1999).

Overview of Streaming Video Practices

Streaming video is currently being put into use in a wide variety of settings. Examples may be found in the literature on streaming video practices in various types of education, from distance learning to course enrichment. Other examples may be found on the use of streaming video in non-educational uses, including corporate communications, news, and entertainment.

Streaming Video Practices in Education

Stanford University’s Stanford Online distance learning program uses streaming video to deliver lectures and other course materials to the students’ home or work computers. Stanford Online uses Microsoft Media Server to stream live lectures and seminars. Course materials are also archived and made available to the students for later on-demand use. Classes in the Stanford Online program consist of streaming video, Web pages with static images and text, and other material provided by the instructor, all displayed inside an Internet browser window (DiPaolo 1999). Stanford Online grew from a research project assessing asynchronous distance education at Stanford University. The project initially utilized QuickTime movies to deliver lectures, but the long download times for the non-streaming video files proved to be a barrier to students. Stanford Online switched to streaming video during the 1996-1997 academic year when the program’s administrators felt the technology had become a viable option for course delivery. Streaming video courses are also made available to students on campus. Students who utilize the Stanford Online courses report the videos contribute positively to the overall learning experience (Schultz & Rouan, 1998).

Streaming video technology is used by the Video Communications Services of North Carolina State University to support the institution’s distance education efforts. Video Communications Services, or VCS, utilizes Real Networks RealServer and RealPlayer software to stream video and other materials. VCS performs live Webcasts and provides archiving and server space for media. Examples of programs offered via streaming video include E-Commerce Seminar Series programs, EPA Air Pollution Distance Education Network programs, and various College of Engineering courses. VCS provides streaming video targeted to a wide range of connection speeds, from a 28K modem to a corporate local area network T-1 connection (Collins 2000).

LESN-Online is the name for Lehigh University’s distance learning via the Internet program. Lehigh University began a satellite transmission-based distance-learning program in 1992 called the Lehigh Educational Satellite Network (LESN). LESN courses delivered via satellite are broadcast primarily to dedicated receiver sites within corporations and other organizations. Students taking courses through the LESN are employees of these corporations, referred to as “corporate partners.” In the fall of 1999, Lehigh University began offering courses via RealNetwork’s RealVideo streaming video. The program, called LESN-Online, is designed to use the Internet to deliver both non-credit and degree programs. According to the literature, streaming video was chosen as the course delivery mechanism for the following reason:

…streaming video provides a richer academic experience for widely scattered learners, and retains more of the character, as well as the quality, of Lehigh course work. (LESN-Online, 2000)

Streaming video lectures are offered on a variety of subjects by the Cornell University Office of Distance Learning as part of the Weill Medical College of Cornell University Grand Rounds Project (n.d.). Each streaming video lecture includes a slide show that is timed to the video of the instructor. Microsoft Windows Media Player is used for streaming the video, and each clip is available at different transmission rates for connections ranging from 28.8 dial up modems to high-speed T-1 connections. Streaming video was chosen for this project due to a belief that students would get more out of the Internet delivery than by actually attending the lecture (Johnson, 1998)

Streaming video lectures are available to support engineering courses through the Lecture-On-Demand program of the Engineering Media Lab at the University of Oklahoma. The Engineering Media Lab uses QuickTime 3.0 progressive download technology. Classes are broken down into segments approximately 12 minutes long, and these segments are then made available for viewing via the Internet. All QuickTime lecture segments may be saved to the user’s computer for off-line viewing if desired. Convenience for the student is given as the reason for the use of streaming video (Engineering Media Lab, n.d.).

The Learning Resources and Technology Services (LR&TS) at St. Cloud State University in St. Cloud, Minnesota, is responsible for providing the faculty with the latest technology and assisting with its implementation. The Learning Resources and Technology Services use both RealNetwork’s RealVideo and Apple’s QuickTime streaming video to deliver lectures, seminars, and other presentations. On-campus curricula and activities are the initial focus of streaming video use, with application to distance education in the future (Miltenoff, 2000).

The University of Alabama Center for Teaching and Learning (CTL) uses RealNetworks RealVideo software to stream video of various University of Alabama mathematics classes and Annenberg/CPB educational programs (CTL Video Library, n.d.). On-campus students can access lectures and video programs at a very high data rate, while off-campus students receive a stream determined by dial-up connection data rates. In addition to computer access, the Center for Teaching and Learning streams video in a preprogrammed rotation over the campus television cable system using a high data rate stream and a computer-to-video interface. The CTL chose streaming video over two years ago to extend the reach and convenience of its video library. Before the implementation of streaming video, CTL library tapes were played over the campus TV system, which limited access to one program at a time, and students were unable to conveniently access the lecture they were interested in. Videotapes had to be manually changed every time a program changed, which was labor intensive. With the RealVideo system, CTL personnel report few problems, apart from occasional server crashes (Bowen, personal communication, October 20, 2000).

The Virtual Play Development Workshop (VPDW) is a project designed to utilize current technology to enable playwrights and directors to collaborate on play development without being in the same geographical location. Originating from the University of Montevallo, the VPDW consists of actors and technical staff from the Division of Theatre at the University of Montevallo. The VPDW uses e-mail, Internet chat rooms, and streaming video to allow the playwright and director to collaborate in real time to produce a finished script that is ready for production in a theatre (Virtual Play Development Workshop, 1999). The VPDW uses Sorensen Broadcaster to produce QuickTime 4.0 streaming video of actors performing a scene from a play under development. The playwright and director will then discuss, via Internet chat, the scene and recommendations for changes to the script or to the way the director directs the actors (McGeever, 2000).

MindQuest.net, a collection of science related links compiled by Randall Oelerich (MindQuest, n.d.) uses a progressive-download Java applet technology to stream videos on biology-related subjects. The videos are provided for study and practice of dissection techniques and for identifying objects seen in the videos (Biology Streaming Videos, n.d.).

A collection of streaming videos can be found at the Video Lecture Showcase (2000). The video clips are examples of classroom teaching techniques. Video clips are organized by subjects, including art, chemistry, and history. The Internet address, streaming video format, and clip length, along with brief comments about the quality and other relevant information clips, are provided for each video clip.

The National Aeronautics and Space Administration (NASA) uses streaming video technology in its Classroom of the Future. The Classroom of the Future is a research and development project that explores the use of educational technology in the math and sciences. NASA streams technology training, the NASA-TV satellite channel and feeds of special events, such as the Pathfinder Mars landing, and a town hall meeting with President Clinton. The presidential town hall meeting, held in May of 1997, marked the first time that a presidential presentation was broadcast live on the Internet. The Classroom of the Future uses RealNetworks RealVideo products for streaming because the program’s administrators believed commonly available products would allow the greatest number of schools and home users access to the content (Shein, 1997).

The United States Naval Postgraduate School uses Microsoft’s NetShow Theater Server to stream video to students. The school gained the capability to stream video and audio when it upgraded its server and network infrastructure in 1999. Future uses of streaming video and audio at the Naval Postgraduate School include distance learning and high-bandwidth video for classroom support (Hamblen, 1999).

Streaming Video Practices in Corporate Communication

Borck (2000) believes streaming video will allow midsize and large companies to cut expenses and improve the value and availability of information to employees. Streaming video can be used for live presentations and for playback of recorded events by those unable to participate in the live events, rather than having employees travel to different locations. Other cost savings come in the form of reduced telecommunications costs. Companies can reduce long-distance telephone charges and eliminate satellite video transmissions by streaming video over the Internet. Other gains for corporations with employees in widely separated geographic locations include bolstering the corporate culture, efficient and timely access to information, and the potential for improving decision-making.

Ford Motor Company makes use of streaming video to disseminate training information about best practices in corporate operations and policies. In the Ford model, plant managers write about their best practices, which are entered into a database as HTML files containing pictures. In April of 1998, Ford began using streaming video to help demonstrate best practices. Other uses for streaming video within Ford include dissemination of manufacturing and product development information (Adhikari, 1998).

The United States Defense Department has begun utilizing streaming video for training and for delivery of speeches from senior military officials. Before the Defense Department began using streaming video, training would have to be done in-person, with high travel costs, or by videotape, which entailed extra mailing costs and slower delivery times. Streaming video enables the Defense Department to train and disseminate information to any location quickly and cost-effectively (Hayes, 1999).

RedHotSalesTV is an Internet-based sales training system that uses streaming videos of Paul Goldner, a professional speaker and sales trainer. Training seminars, which have been available in person, are made available in a streaming format that includes a synchronized PowerPoint presentation and downloadable workbook. This format is attractive to sales personnel, who can participate in training sessions at convenient times without additional travel. Online training is not expected to completely replace in-person training, however, due to the importance of practicing interpersonal skills, and due to varying connection speeds which may prevent the sales trainee from getting as much out of the program as a trainee with a faster connection (Rasmusson, 2000).

Streaming Video Practices in News and Information Dissemination

Williams (2000) notes that streaming video can increasingly be found on news and information Web sites. The online versions of many traditional newspapers now feature streaming video of stories. Streaming video is often seen as an opportunity to keep viewers coming back to television station and newspaper Web sites. Many companies own newspapers that also own television stations, and the lines between the two are increasingly blurred. For example, USAToday.com, owned by Ganett Co. Inc., streamed video supplied by Denver television station KUSA-TV, also owned by Ganett Co. Inc., of the Columbine school shooting tragedy. The recent collaboration between traditionally print media and traditional broadcast media arose due to a realization that both types of media had something to offer each other when creating an online presence. Print media brought in-depth stories and broadcast media brought video and sound. Through content-exchange agreements, newspapers and television gained the ability to offer their respective Internet audiences the information they wanted. David Westin (as cited in Williams, 2000), president of ABC News illustrates this with the following quote:

We’re all seeing the explosion in multimedia news and information, and we certainly had identified the need for us to find the proper alliance with a print news organization. And I understand The New York Times had felt a similar need to work with a video news provider, and so it’s the larger revolution that we’re seeing in news information. (p. I35)

One driving force behind the media’s move to the Internet is the creation of a focal point for enhanced community interactivity. Loyal audiences create a community around a Web site, and those communities become potential revenue sources. Streaming video is seen as a way of keeping people on a Web site (Williams, 2000).

Mainstream news organizations are not the only ones taking advantage of streaming video. Many small, independent news organizations with names like Free Speech TV are taking advantage of the Internet to provide an alternative to traditional news reporting. These organizations see streaming video as an excellent way to get their message out to a worldwide audience. The 1999 Seattle World Trade Organization Convention, which was disrupted by large numbers of protesters, is one example of an event that was heavily covered by these organizations (Paton, 1999).

Wolf (2000a) noted that at the 2000 Republican National Convention, 35 Internet businesses reserved space in the convention media complex’s Internet Alley, a 10,000 square foot space on the floor of the Philadelphia First Union Center, set up specifically for Internet operations. At the convention, streaming video was used to provide live 360-degree rotating camera shots, allow Internet users to control various camera feeds from C-Span, and provide video of convention events. Problems were reported with Internet connections, the quality of the streaming video, and content that was irrelevant. Convention and media officials are optimistic that the number of users of streaming video and the streaming quality will improve to the point that, by the next election, Internet coverage using streaming video will be just as important as traditional media coverage (Wolf, 2000b).

Streaming Video Practices in Entertainment

Streaming video can also be found on many entertainment and informational Web sites such as “The Teachings of Dr. Gene Scott” (n.d.), which contains various philosophical and religious streaming videos from the site’s principal, Dr. Gene Scott. HBO.com offers streaming video trailers from upcoming shows and special events such as a live 30-minute Webcast of comedian Dennis Miller (The Net’s Next Battle Royal, streaming video on the Internet, 1999).

The movie Quantum Project is a 37-minute feature film created specifically to premiere and be played primarily over the Internet. Using streaming video as the distribution method, the filmmakers learned that producing a movie specifically for the Internet brought many challenges, such as deciding on the best way to shoot the movie to give the video the look they desired after considering the effects of the video compression that would be required. The movie was not made with profits in mind, but was a first attempt at making a Hollywood movie specifically for viewing over the Internet. As producer Stephen Simon notes,

For the rest of the history of the Internet we will always be the Internet version of The Jazz Singer. No one remembers what the second talking film was, but everyone remembers what the first one was. (Caronia, 2000, p. i14)

Hoffer (2000) used streaming video to deliver documentary footage to Eveo.com, an Internet company that specializes in distributing the work of independent filmmakers. The subject of the documentary was Carnival season in Brazil, and was shot over a five-week period. Hoffer shot and edited all the footage on location in Brazil using an Apple Powerbook, and the challenge was to be able to stream the edited footage back to the United States from whatever location he was at in Brazil. Hoffer found that streaming video using dial-up access over Brazilian telephone lines was both unreliable and very expensive. Hoffer next attempted to stream video from the offices of various local Brazilian Internet service providers, but this too proved to be unreliable and troublesome. In the end, Hoffer sent edited tapes back to the United States via express mail.

Pseudo Programs produces about 200 hours of streaming video content from studios in New York City. Pseudo Programs is positioning itself as a leader in the developing Internet broadcasting industry. Shows produced for the Internet are highly targeted niche programs directed at members of existing subcultures who consider the Internet their primary source of information. Programs range from professional wrestling to lifestyle shows. Most of the shows are streamed live, and an online chat room provides interactivity. Psuedo Programs does not have accurate numbers on the number of viewers watching their Webcasts, but estimates that over 500,000 video streams are generated each month. As in traditional television, streaming video shows include breaks for commercials because Pseudo Programs does not believe Web banner ads will generate sufficient advertising income (Holt, 2000).

Kerschbaumer (2000) notes that CameraPlanet.com uses a unique model of generating streaming video content. CameraPlanet.com visitors submit Story ideas via e-mail. If the story is interesting, CameraPlanet.com will help the visitor produce a streaming video for the Web site. The goal of the site is to create a sense of community, and the company believes that streaming video, produced by the viewer, drives that process. When the users produce the content on a Web site, they become participants rather than passive viewers, which adds to the sense of community for which CameraPlanet.com strives.

Two companies that host streaming video content for users are ClipsCom and Visualize Video. Hosting involves storage and Internet access only. All content on both sites is created by individual users who then upload their content to ClipsCom or Visualize Video. This hosting service provides users, who may not have access to streaming video server hardware and software, the means to distribute their content via the Internet. Streaming video clips can be personal ones, or they can be business related. Both companies make use of extensive arrays of streaming video Web servers (Johnson, 2000).

Research on the Effectiveness of Web-Based Instruction

Streaming video is an Internet-based content delivery method. Thus, for instructional purposes, streaming video must necessarily be used in a Web-based instruction system (WBIS). Web-based instruction systems arose from the merger of the general use of computers in education and the use of videoconferencing. Liegle and Meso (2000) note that a WBIS allows for the delivery of knowledge to a well-defined set of learners via the World Wide Web by enabling both instructors and learners to fulfill all of the roles found in a conventional learning environment. Web-based instruction systems can be broken down into two main delivery methods: (1) a tutoring style uses a one-to-one mode of communication between the system and the learner, usually with some sort of content customization for each learner, and (2) a lecturing style which uses a one-to-many mode of communication between the system or instructor and the learners, which does not allow for much customization of content.

A Web-based instruction system may make use of the Internet in one of two ways: (1) Web-mediated where the Web is the predominant medium through which learners interact with the course material, and (2) Web-supported where the Internet is used to support a traditional instructional environment (Janicki & Leigle, 1999, cited in Leigle & Meso, 2000).

Chute, Thompson, and Hancock (1999, p. 53) note that Web-based instruction allows training and instruction to be delivered and updated quickly. Students can then access that information from anyplace, at anytime. Updates can be performed on the Web, eliminating the need to mail content updates, or deliver them in person. Additionally, content can remain accessible on the Web, allowing students later access for reference or continuous learning.

Web-based instruction does have limitations. Without the external motivation of regular class meetings, some students who lack self-motivational skills may be at a disadvantage. If the system itself, either the structure of the instruction system or the technology used to manage and deliver the instruction, is poorly designed or unreliable, then the learning process can be inhibited. Additionally, if the instructor and students are uncomfortable or unhappy with the system, that discomfort may be a distraction that inhibits learning (Chute, Thompson, & Hancock, 1999, pp. 53-64).

Wegner, Holloway, and Garton (1999) examined the impact of Web-based instruction on student learning. The question posed was whether there would be any significant difference in student achievement, as measured by teacher-prepared tests, between students taking a class using a traditional in-class method and students taking a class using a Web-based instruction model. Graduate students in a principal certification program made up the control and experimental groups. The in-class group received instruction in a traditional lecture with small group activity format. The Web-based instruction group received instruction via a problem-based learning model. Problem-based learning involves the understanding or resolving of a problem without the traditional lecture. Students in a problem-based learning environment are expected to apply problem solving and reasoning skills, and to search for any knowledge and information needed to successfully solve the problem. Instructors in a problem-based learning environment fulfill the role of coach or guide, avoiding traditional lecture as much as possible. The results showed no significant difference between the two groups on measures of student achievement. Comments made by the students on a course evaluation survey revealed no negative effects of the Web-based instruction on the students’ perception of their learning.

Student achievement is one measure of the effectiveness of Web-based instruction. Quality of instruction is another, and Ryan (2000) noted that the newness of Web-based instruction raises questions about quality assurance. One primary question was whether or not Web-based instruction can be judged by the same quality standards as traditional lecture classes. To explore this question, a construction equipment and methods class at the University of Oklahoma College of Architecture was offered in both a traditional lecture format and in a Web-based instruction format during the spring 1998 and spring 1999 semesters. The University of Oklahoma College of Architecture NonStudio Course Evaluation was used to gather students’ perceptions of instructor performance, course content, and self-evaluation. The numerical ratings for both methods of course delivery revealed no trends or evidence of different quality perceptions on the students’ evaluation forms. Final course grades for lecture participants and Web-based learning participants were not significantly different for either semester. Issues of quality for students in both delivery methods were the same, which led to the conclusion that Web-based instruction classes should be evaluated in the same manner as lecture classes.

While other studies have examined achievement and quality, a 1997 study by Edwards and Fritz suggests that students are demanding and willing to pay for education and learning experiences that can be delivered at the time and place where that learning is most relevant and convenient. A study to examine alternative delivery formats assessed students’ perceptions of outcomes of various educational media formats. Three different class formats were examined, each one using Web-based instruction in a different context, from online lecture materials to supplementary course material. The study revealed that students perceived strong learning outcomes from Web-based materials. Web-based learning was perceived to be enjoyable, interesting, and helpful for learning concepts and applications. From the sample studied, the effectiveness of Web-based instruction appears to have been influenced by student access to material. The correlations between access and perceptions of independent learning and mastery were strong, although not always significant.

A recent meta-analysis of the literature by Jung and Rha (2000) concerning Web-based instruction found that studies comparing the effectiveness of distance education with that of in-class education or the effectiveness of different technologies showed that there is no general learning superiority for one type of technology or delivery over another. Some studies were found (Daugherty & Funke, 1998; Hiltz, 1994; Jonassen, Prevish, Christy, & Stavrulaki, 1999; Thompson, 1996, as cited in Jung & Rha, 2000) that showed online instruction led to significantly better results on examinations, problem solving, and in students’ acquisition of information technology skills. Hiltz (1994, as cited in Jung & Rha, 2000) noted that the online treatment outperformed the conventional treatment when the instructor for the online treatment incorporated more interventions geared to students’ characteristics than the competing treatment. Factors suggested by Jung and Rha’s meta-analysis affecting the effectiveness of online instruction include instructional design factors such as flexible course structure, frequent feedback, functional visual layout and multiple zones of content knowledge (McLoughin, 1999; Stevension, Sander, & Naylor, 1996; Vrasidas & McIsaac, 1999, as cited in Jung & Rha, 2000). Social factors such as interpersonal interaction and social integration also affect the effectiveness of online learning (Anderson & Harris, 1997, as cited in Jung & Rha, 2000). Finally, students’ personal factors such as prior knowledge of subject matter, self-sufficiency, introversion, and responsibility for constructing their own knowledge were found to be related to achievement in online learning (Biner, Bink, Huffman, & Dean, 1995; Bullen, 1998; Hill & Hannafin, 1997; Hillman, 1999; Jonassen, Prevish, Christy, & Stavrulaki,1999; Laffey, Tupper, Musser, & Wedman, 1998; Limbach, Weges, & Valcke, 1997; Naidu, 1997; Shneiderman, Borkowski, Alavi, & Norman,1998; Wishart & Blease, 1999, as cited in Jung & Rha, 2000).

Research on the Effectiveness of Video in Non-Streaming Video Applications

A number of researchers have looked at the effectiveness of video in education over the past 50 years. Studies have examined a variety of video delivery methods, as well as the overall effectiveness of video for learning. Applications of video have included broadcast television, satellite delivery, videotapes, and compressed video over dedicated connection lines, normally referred to as videoconferencing. The use of the term video in this context differs from streaming video mainly in the context of the newness of streaming video technology. Since both streaming video and other video delivery methods have moving images in common, however, other research studies on the effectiveness of video in non-streaming video applications bear examination.

Overview of Video Technologies

Chute, Thompson and Hancock (1999) offer a useful overview of video technologies in education. One-way video broadcasts can be characterized by the transmission of video signals in only one direction, from the instructor to the students. Examples of this include satellite transmission and over-the-air television broadcasts. Communications from student to instructor take the form of phone calls, faxes, and e-mail. Videotapes have been used for many years in educational settings. Videotapes make training or other educational content available in a self-paced manner, allowing students to watch the tapes at a time and a place convenient to them. Video and computer-based training technologies can be combined to allow students to experience a variety of training media as they complete units of instruction. When computers and video are combined, the computer can provide tutorials, simulations, drill and practice sessions, and other data processing tasks such as assessment and course management. The video is used to supplement the delivery of the training content, which is controlled by the computer. This method of presentation is one-way, with interaction only between the learner and the computer in a highly structured, programmed manner. Two-way video distance learning systems provide video and audio communications in real time between instructors and students. These systems allow more interaction between students and instructors than videotapes, video transmission, or video and computer-based training. Full motion video is a term that is used to describe a two-way video system that delivers picture quality comparable to commercial broadcast television. These systems typically use fiber optic, satellite, or microwave transmission, which are fairly expensive compared with the newer compressed video systems. Compressed video systems use signal-processing methods that reduce the amount of transmission bandwidth necessary. Signals are usually sent over the switched telephone network, which allows compressed video transmissions to use different bandwidths depending on need and budget.

Belanger and Jordan (2000) discuss the advantages and disadvantages of three different applications of video in distance learning. The first, teleconferencing, is defined as a synchronous mode of distance learning using audio, data, and video that requires all learners in a course to be connected to each other and to the instructor for the duration of the session. Belanger and Jordan note that videoconferencing can be implemented at either of two levels: large scale facilities, which involve rooms or auditoriums and allow interactivity between individuals at different facilities; and desktop videoconferencing, which uses personal computers to interactively link individuals over the Internet or local area networks. Teleconferencing advantages cited include a video component that simulates face-to-face interaction, geographic independence when connecting via the Internet, and, in the case of desktop videoconferencing, when an organization already uses personal computers, low operational costs. Disadvantages of teleconferencing include high transmission bandwidth requirements for acceptable-quality interactions, limitations on the number of simultaneous users, and high implementation costs if an organization has no preexisting computer or audio-visual infrastructure.

Belanger and Jordan (2000) describe the second video application, videotape, as having a simple delivery mechanism. Content on videotape can be viewed in a room using video projection and display equipment, or even in the student’s home. Videotapes can also be combined with other learning tools, and digitized for delivery on computer discs. Three distinct advantages are cited for videotapes: (1) temporal independence allows instructors to create videotapes at any time and for learners to watch a videotape at a time most convenient for them; (2) geographic independence allows videotapes to be distributed and viewed worldwide, with only limited requirements, such as a television and videotape player; and (3) overall cost of delivery to a large number of students due to low costs of videotape duplication and archiving. Disadvantages noted include a lack of interaction between instructors and students, a lack of control over the learning environment, and a limitation of a passive mode of learning. Videotapes are also difficult to revise, often requiring the entire program to be redone. The third video application discussed is video tele-training, which is defined as using live video and audio to teach a course in real time to one or more remote locations, in a manner similar to television broadcasting. Advantages cited by Belanger and Jordan include up-to-date course content covered in real time, interaction between learners and instructors, often by electronic means such as faxes, e-mail, or telephone calls, geographic reach without the use of dedicated telecommunications lines, and lower operational costs when delivering courses to large groups of learners at multiple remote locations. A disadvantage noted by Belanger and Jordan is geographic and schedule dependence, where students must travel to the remote site at the time of the video telecast to receive course content. Another limitation noted is the need for increased coordination and support personnel to ensure the smooth delivery of a course. The high cost of implementation if no prior infrastructure exists is also cited as a disadvantage. Belanger and Jordan conclude that hybrid delivery mechanisms, which do not tie a program or student down to one video delivery mode, provide the optimum environment for distance learning students or trainees.

Research on the Effectiveness of Video in Educational Applications

Before video such as television or videocassettes became widely available as a means for delivering instruction, films were used as a method for illustrating concepts or delivering content using moving pictures. Hoban (1949) explored some issues related to learning from films. One concept was that motion pictures, or films, are not simply photographs projected in sequence to convey the impression of motion. Films are more familiar as entertainment media than as instructional media. This leads to a compromise between instruction and entertainment, with the instructional aspects having higher priority. Films influence behavior and convey a message by combining three symbolic forms of expression. These symbolic forms are photography, or images, music, and language. Another concept was that of the dynamics of learning from films. Four factors were identified in relation to instructional films: (1) context and novelty, (2) feeling tone and rewards, (3) identification, and (4) closure. Context and novelty refers to the balancing between context, or familiar elements, and novelty, or unfamiliar material. A good ratio for learning has a maximum of familiar elements and a smaller amount of new elements. Feeling tone and rewards refers to the affective message of the film. A pleasant tone and rewards for the audience such as humor or audience participation or involvement are examples of this factor. Identification means getting the viewers to project themselves into the film and identify with situations or content that are presented. Identification also involves introjection, which is the taking on of qualities or behaviors of a selected person.

Introjection in an instructional film means stimulating the audience to do something or accept something presented in a film. Closure in the use of instructional films is an extension of the concept of introjection. After the viewer has taken on the qualities or forms of behavior set forth in an instructional film, the film should stimulate the viewer to seek closure. This is accomplished by leaving the audience with the feeling of personal responsibility for further study or for putting concepts into practice. Creating a mechanism for the student to seek closure would add to the instructional value of a film.

The Toronto Board of Education (1972) undertook a study of television as a teaching aid. Various types of lesson presentations were employed in the experiment, including interviews, demonstrations, illustrated lectures, direct instruction, and remedial teaching. Three subjects, art for middle schools, science for elementary schools, and guidance for high schools were chosen as the basis for the lessons. The report noted that telecast portions of the lessons stimulated pupil interest and motivated expanded activities. Additionally, a conclusion reached was that more than one presentation of each telecast was necessary for optimum effect upon learning and retention.

Gropper and Lumsdaine (1961) examined the effectiveness for learning of active student response during a televised lesson that had been programmed. Programming here refers to (1) the reduction of lesson content into small steps and the logical sequencing of these steps; (2) the encouragement of active student response at each step, followed by reinforcement; and (3) the preliminary tryout of the lesson to determine the probability that the programmed lesson can elicit correct active responses at each step. The experiment performed consisted of two lessons, one on the effects of heat, and one on nuclear reaction. Each programmed version of the lesson was contrasted with a conventional lecture, both of which were broadcast simultaneously to their respective groups. The results tended to support the effectiveness for learning of active student response to programmed material, with higher IQ students showing greater gains than lower IQ students. Gropper and Lumsdaine interpreted this to mean that programmed television lessons directed toward the average student may be inadequate to elicit responses from below-average students. Gropper and Lumsdaine also note that in a conventional television lecture, there is no provision for reinforcement. In a programmed television lesson arrangements for reinforcements are included, much as in an in-person lecture.

Hunt (1961) noted that a televised program series for teachers designed to teach procedures and practices of teaching reading skills had a significant impact on reading instruction in the classroom. The study consisted of 15 half-hour programs prepared by an expert staff and telecast at different times by a local television station. Teachers were grouped by either program viewing or non-viewing. The results of the study demonstrated that the television program did have a measurable effect on the observed classroom performance, activities, and attitudes of viewing teachers. Hunt also noted that viewing the television series had a significant effect on the attitudes of viewing parents. Hunt concluded that open-circuit, or broadcast, television can be used to influence the performance and attitudes of teachers and parents with respect to a particular educational concept.

Brown, Toffel and Lundy (1961) conducted an experiment to determine the effectiveness of television instruction in teaching high school chemistry in Alabama schools. For the project schools were classified as either using television or not, condition of laboratory at the school, qualifications of chemistry teacher, and mostly white or mostly non-white schools. The televised chemistry course consisted of three 30-minute lessons per week over the course of the school year, all broadcast by the Alabama Educational Television Network. Not all demographics examined had complete data. Some statistically significant results were reported, however. Statistically significant differences were obtained between students of high and low mental abilities, with high mental ability students performing better with televised lessons, when the quality of laboratory facilities and teacher training were high in both groups. Mostly non-white schools using the televised lessons scored significantly higher than their counterparts not using televised lessons. Further results were inconclusive due to reported problems with controls in the research design.

Conlin, Borich, and Keel (n.d.) compared a telelecture, defined in the study as remote teaching by broadcast television with two-way audio hookups at multiple locations, with a traditional lecture in a series on dairy herd improvement. One lecture was prepared for both telelecture and regular lecture groups in the study, and pre- and post-tests were used to evaluate the effectiveness of both types of lecture. The results revealed no significant differences between the televised lecture and regular lecture. Conlin et al. noted that the results point out that learning can take place by both methods. Another conclusion reached is that rather complex topics can be handled by telelecture. Conlin et al. finally note that a well-planned educational activity can consistently cause knowledge transfer and does not rely only on factors such as location, time of day, and attitude of the teacher.

Chu and Schramm, in a 1975 meta-analysis of the research on the effectiveness of instructional television, found that instructional television works best when it is made an integral part of instruction. Additionally, Chu and Schramm note that attention to the basic requirements of good teaching, such as simplicity, good organization, cues for the student, and practice contribute more to the effective use of television than any special trait of television. While pointing out that broadcast television is a one-way medium, without inherent feedback from student to instructor, Chu and Schramm point out that instructional television does have certain advantages. These include one teacher reaching a larger number of students, the potential for higher quality visual and auditory experiences and demonstrations than normally possible in a classroom, and the delivery of education to remote areas.

Brown (1975), in a study of learner responses to the use of television, surveyed students in University of Mid-America educational television courses to determine attitudes towards and the effectiveness of instructional television. In the four University of Mid-America courses surveyed, television was designed to be the principal instructional medium. Courses would not be conventional televised lectures, but would instead be high-quality affective-oriented programs. The determination was made that while many courses focus mainly on direct impartation of content knowledge, a more effective use of television was to focus on affective elements of learning, such as course enjoyment and maintenance of learner interest. The survey by Brown was designed to test the effectiveness of television courses designed with an affective orientation. Brown concluded that enrollees in courses exhibited a low tolerance for any television component material not perceived to be directly instructional, such as techniques perceived to be strictly for the learner’s entertainment. This led Brown to question the decision by the University of Mid-America to reject a classroom-lecture style instructional television program. Brown also noted that the content of the television programs should be integral with the content of the other components of the course, and the television component itself should provide significant learning, without simply being a reiteration of material presented elsewhere in the course.

Boverie, Murrell, Lowe, Zittle, Zittle, and Gunawardena (1997) analyzed the interaction between the learner and the instructor in a distance learning context in a study that examined three research questions: (1) the importance of providing live broadcasts rather than taped instruction, (2) the importance of providing social presence in producing learner satisfaction, and (3) the importance of providing interaction between the learners and the on-screen instructor. The study used two interactive satellite television distance-learning programs designed for primary schools. One was a science program called “Geonauts,” and the other was a foreign language program called “Elementary German.” Each program was delivered by one-way video, two-way audio satellite broadcast, with interaction taking place during the broadcast by telephone, e-mail, and fax. Data were collected by mail surveys and case studies. Boverie et al. reported no significant difference in student satisfaction when watching the German program either live or taped. For the Geonauts program, however, a significant difference was found, with students indicating more satisfaction with videotape than with the live satellite broadcast. For teachers, no significant difference was found in satisfaction levels between viewing the program live or taped. Analysis of the data revealed a moderate to high relationship between the social presence of the television instructor, which includes elements such as the teacher’s humanizing qualities and instructional style, and overall student satisfaction in both programs. The importance of providing interaction between learners and the on-screen instructor was analyzed to determine if there was any difference in student satisfaction with the programs and interaction with the television instructor during the program. No significant difference was found in student satisfaction for either program during broadcast times or outside of broadcast times. A significant difference was found, however, in teacher satisfaction when the class could call in and talk to the television instructor during the television Geonauts program. Teachers were more satisfied if their classes could call in and talk to the television teacher outside of broadcast times, indicated by an overall significant difference in teacher satisfaction. Boverie et al. concluded that satisfaction with the program could be predicted by social presence and interaction, and that the results indicated that watching the programs live had the same effect as watching them on tape.

Research on Broadcast Television in Education

Bates (1984) noted several distributional factors of broadcast television compared to other forms of television such as cable, satellites, and cassettes for distance teaching. Almost every household in developed countries can receive standard broadcast transmissions of the national networks. Since most households in these countries already have a television set, the cost of broadcast distribution is free after the initial production charges are figured. Distance teaching then experiences several educational benefits from the universal access to broadcasting. The first of these is the ability of the program to carry essential teaching material, since all students should have access to the broadcast. Another is the publicity offered by having educational programs broadcast, which should boost recruitment efforts. A third benefit, if high-quality television production techniques are used, is an increase in motivation and interest among students who work independently. The last is the benefit to the general public of having alternative educational programs available to the public. Bates remarks that the distributional advantages of broadcast television depend upon suitable transmission scheduling, with the difficulty of obtaining favorable transmission times a major limitation of broadcasting.

Research on Videocassettes in Education

Brown (1984) compared the educational advantages and disadvantages for distance education of videocassettes with broadcast television. Brown noted that videocassettes are like broadcast television in that they combine moving pictures with sound, but unlike broadcast television in that they can be viewed in ways that are independent of pre-determined transmission times. Videocassettes can act as a back up to television broadcasts. Students can record programs and can request tape copies of broadcast programs for viewing at a time determined by the student. Brown reported a significant demand for videocassettes at the British Open University during a pilot program designed as a back up for regular transmission. Brown noted a significant increase in program viewing rates for students who viewed videocassettes plus broadcasts versus students who did not view videocassettes. Students reported three main reasons for borrowing cassettes: access, control, and ability to view the programs at their own pace. An evaluation of an Open University course designed to be delivered by videocassette yielded some significant findings. Brown noted that it is possible to design educational video materials, which use the characteristics of the videocassette medium more effectively than simply recording television broadcasts on cassette, such as segmenting the program for frequent pauses for reflection and further activities. This allows a high degree of integration with other course materials and a higher level of student-to-video and student-to-student interaction. Brown also reported differences in the ways in which students responded to videocassettes, depending on whether they viewed the videocassettes as individuals or in groups. The videocassettes were designed for viewing by a group with questions on the program designed to stimulate discussion among the viewers. Individual viewers were unable to discuss the topics with other students and were consequently more concerned with finding the right answers to what were intended to be open-ended questions. Among the groups of viewers, the suggested discussion topics did generate lengthy debates, although students tended to focus attention on recording factual detail rather than on observation and analysis of overall relationships. Brown concludes that video cassette design would likely take two different paths: (1) highly student-interactive video cassettes with frequent questions, guidance and feedback for individual students; and (2) more open-ended stimulus material for group viewing, with questions designed to stimulate discussion within the group.

In a study of the educational impact of a videotape-based course delivery system at a midwestern two-year college, Willett (1986) noted that one of the appealing features of a telecourse, or videotape-based course, is that it is a self-paced system. Other appealing features include flexibility and availability of materials at off-campus locations. The study sought to determine what percentage of students continued to take courses in the telecourse format, or preferred taking telecourses. The results showed that students who enrolled in the telecourses were primarily attempting to fill a course load, and were traditional college-age students, rather than adult students. Reenrollment patterns suggest that the telecourse students did not stimulate further interest in the videotape-based delivery method. Willett concluded that further research needed to be performed to increase the impact that a telecourse system could have on nontraditional student populations, and to increase student reenrollment in a telecourse instructional delivery system.

Research on the Combination of Videocassettes and Computers in Education

Mahendran and Young (1998) evaluated the use of advanced technology videotapes, defined as an integration of computer and laboratory simulations of advanced engineering concepts, at the Queensland University of Technology to improve the quality of lectures and to replace certain laboratory teaching. Engineering faculty at Queensland University of Technology believed laboratory sessions to be useful in improving the understanding of basic concepts and the real behavior of structures and their components. Prior to the study, the amount of laboratory time began to be cut back, so an alternative method of delivering the knowledge was attempted. A new method was proposed for laboratory teaching that used advanced computer graphics, data visualization, and video technologies to simulate laboratory sessions and to improve the teaching and learning of basic concepts and theory. Videotapes were produced using advanced video production equipment. Videotapes typically consisted of an introduction, a list of objectives, relevant theory and design rules with simulations, and a conclusion. Simulations were composed of three parts: (1) annotated 3D images and animation sequences of selected representative structures and their components, (2) a videotaped laboratory experiment capturing the important parts of testing the structures from the prior image sequence, and (3) videotape of full scale structures and their components to demonstrate the concept’s connection to real life. The project was evaluated to determine its effectiveness. The first phase of the evaluation consisted of a survey of the academic and technical staff members of the faculty of Built Environment and Engineering at Queensland University of Technology. Results of the survey showed that faculty believed the videotapes would improve understanding and increase learner control. The second phase of the evaluation consisted of an experiment in which two groups of nine second-year, civil engineering students were given formal lectures on buckling of steel with and without the use of the advanced technology videotapes. Both groups scored approximately the same on the ability to use design formulae appropriately. On the second part of the test, the students who saw the videotapes outperformed the non-videotape students on questions of understanding buckling behavior. This was explained by comparing the videotapes to the use of traditional laboratory experiments and field trips to assist in the understanding of buckling behavior. The third phase of the evaluation studied the effects of the videotapes on the learning process. Six second-year undergraduates were shown a videotape and were asked a series of questions regarding attitudes towards the videotape and questions on the use of data visualizations and section design. The results demonstrated that the videotape was a worthwhile learning resource for use in the lecture, and in particular, that the computer simulations were seen as very important and useful by the students in gaining an understanding of the subject matter. Mahendran and Young concluded that the videotapes would produce a range of significant benefits, such as replacing the laboratory teaching in the videotape subjects.

Madachy and Miller (1978), in a report on Gallaudet College’s use of computer-aided instruction (CAI) and videotapes as methods for improving the English language skills of the hearing impaired, note that integration of video tapes and CAI seemed to offer definite advantages over the use of either medium by itself. CAI provided the capability for drill and practice in manipulating various English language structures, and videotapes provided the ability to present and illustrate certain language concepts. Madachy and Miller noted that students could benefit from materials that would help them master both the language concept and the corresponding form or structure that communicates that concept. The experimental program described by Madachy and Miller begins with students receiving CAI-based drill and practice in the use of appropriate language structures. After the CAI sequence, students are shown video sequences dealing with the same structures. The results from a sample of approximately fifty students showed a marked improvement in post-test scores compared with pre-test scores. Madachy and Miller conclude that the combination of videotapes and CAI represented alternative ways to help improve the English language skills of the hearing impaired.

Vonfeldt (1977) proposed a system that combined elements of computer-assisted instruction and instructional television. The proposed system would provide instructional gains for teaching concepts that were unavailable through any other available system of the time. The system was to comprise a computer, videotape player, television, and computer storage disk. The system was to include the computer-based capabilities for individualizing instruction, feedback, and performance recording, and the capabilities of television, including sound, high-quality pictures, and random access of video sequences. Vonfeldt noted that the creation of a computer-based interactive television system had strong potential for individualized instruction and teaching concepts requiring motion.

In a 1987 essay on the state of interactive video, Laurillard described interactive video as using either videodiscs or videocassettes as the video medium in conjunction with a microcomputer. Using this definition of interactive video, lessons run entirely under the control of the computer program, which controls the video machine, and is also responsible for text overlay while the video is playing. This style of instruction is further defined as programmed learning, where the microcomputer controls the pace and direction of instruction based on student performance on tests. Problems with this form of instruction include an inability to explore student interest and queries as they arise and a passive learning mode for the student. Laurillard notes that interactive video should not confine itself to machine control, but should investigate the possibilities of student control. A system that utilizes the random access capabilities of videodiscs allows instruction to be individualized. Video discs would allow fast access to any frame or scene on the disc, creating the possibility of nonlinear instruction, which would give students the opportunity to create their own path through a body of knowledge. Laurillard suggests that interactive video could be a valuable research tool for exploring how students use and learn from new technology.

Research on Two-Way Interactive Television in Education

Hart, Hart and Benavides (1992) describe California State University-Fresno’s experience with the establishment of a rural instructional television fixed service (ITFS) distance education program. ITFS, a special over-the-air transmission system licensed by the Federal Communications Commission, was chosen over other technologies such as satellite delivery, point-to-point microwave, dedicated line compressed video, or a combination of the preceding technologies. The choice of ITFS was made due to the geographic characteristics of the university service area, availability of frequencies, and the relative construction and operation costs. Additional factors such as a lack of advanced ISDN or fiber-optic lines and the high costs of two-way full-motion live video interaction using microwave or cable television technologies influenced the choice of ITFS delivery. Following an evaluation and planning phase for the management infrastructure of the proposed distance education program, the design of the distance education courses themselves was considered. The format of the lectures was examined, and the conclusion reached that the lecture format should take the medium and the audience into consideration. The television medium tends to distort the perception of time in the viewer’s eye, which entails a careful planning of the use of time. Television allows dynamic lectures that may incorporate many different media and technologies to which instructors in traditional classrooms do not have access. A lack of direct eye contact and interaction between instructor and student must be accounted for. Passive lectures via television may lead to boredom or a feeling of isolation on the part of the student. Interactivity may be implemented by the use of role-playing, simulations, class discussions, two-way audio interactions, and computer-assisted programs. Hart et al. conclude that distance-learning lectures must be dynamic and interactive to be effective.

Miller, McKenna, and Ramsey (1993) contrasted graduate level education students in instructor-live and instructor-remote learning conditions in a two-way interactive compressed video system to examine the question of content mastery while learning in live and remote conditions. Another research question involved the students’ feeling of belonging to group discussions while in either condition. The experiment used a compressed video system that ran over a dedicated T1 line. A T1 line is the equivalent of 24 regular telephone lines and runs over the existing telephone network. Two lecture-oriented courses were used in the study, one in educational research and the other in the psychology of reading. Students’ attitudes towards their learning experience was assessed with four self-reported attitudinal items scored on a 10-point scale. The final examinations of both courses were used to assess content mastery. Miller et al. reported that students did not feel that their mastery of content was as adequate when the instructor was in the remote condition as when the instructor was in the live condition. In both classes, however, students in the off-campus sections felt that their mastery of content in the remote condition was as successful as in the live condition. This revealed a main effect of live versus remote condition attributable to the on-campus groups rather than the off-campus groups. Another result, regarding the feeling of belonging to class discussions, followed the same pattern as the feeling of content mastery. A significant difference was found between students in the live versus remote condition, with students in the live condition reporting feelings of belonging less to class discussions than students in the remote condition. The final result reported revealed a significant difference between groups on actual content mastery, with students in the live condition scoring higher on the final examination than students in the remote condition. Miller et al. conclude that the study raised concerns about the impact of distance learning on both the attitude and achievement of college students, and that live and remote conditions are not equivalent for proficient adult learners.

In 1994 Cochenour and others surveyed compressed video applications in education and the private sector to determine usage trends and possible patterns for the future direction of compressed videoconferencing and networking. Compressed video is defined in this survey as the use of digitized video transmitted over reduced bandwidth connections, such as T1 lines. The survey results revealed that cost was the primary reason for selecting compressed video, with T1 lines by far the most common transmission method. The respondents were asked to describe the applications currently using compressed video, and a wide variety of answers were obtained. Videoconferencing, education, and administration were the most common uses. Other uses included research, court hearings, and consultation. A trend revealed by the survey was toward the use of lower transmission rates. This was determined to be due to reduced costs for conferencing at lower transmission rates although it was noted that transmission quality is reduced at the lower rates.

The University of Maine System offers an interactive television distance education program through its Community College of Maine designed to deliver access to higher education to all of the citizens of Maine. The system supports two-way audio and video and uses a combination of dedicated fiber optic lines between each college campus and point-to-multipoint microwave transmitters to high schools, off-campus university centers, and technical colleges. Ongoing effectiveness studies are used to assess student perceptions of the interactive television system, student academic performance, and faculty perceptions of their teaching experience and of the interactive television system. Results from the assessments reveal that student academic achievement was well above average, and that students were generally satisfied with the instruction they received in their courses although many expressed a desire for more interaction. Faculty generally reported a positive teaching experience over the system although some concerns with the adequacy of classroom interaction with their students were reported. A disadvantage of teaching over the interactive television system given by faculty was the occurrence of logistical problems such as distribution of materials and initial difficulty of dealing with multiple sites. Advantages cited by faculty for teaching over the interactive television system included videotapes of classes that students could review, opportunities to use advanced technologies in the classroom, and increased access for students in remote areas (Lyons, MacBrayne, & Johnson, 1994).

In a 1997 study, Jones and Klopfenstein evaluated the effectiveness of combining T-1-based compressed interactive video together with an Internet-based interactive Web page component. The primary question of the study was whether or not the quality of instruction delivered to both on-site and remote classrooms could be equalized through the multimedia combination of interactive video and the Internet. An additional question posed examined the impact on the instructor’s classroom of extending the classroom to a remote site. Jones and Klopfenstein used a new electronic media telecommunications class at Bowling Green University as the focus of the study. The course was transmitted to a reception site by means of a T-1-based compressed video system. A class Web page designed to provide student with asynchronous on-line assistance, tests, and resources provided the Internet-based interactive portion of the class. Due to a small sample size, no statistical analysis was conducted on data gathered from the survey distributed to the students in the course. Jones and Klopfenstein report that students felt the interactive television lecture was as effective as the in-person class presentation. All of the students gave positive responses on questions concerning the usefulness of the course Web page. Results were noted, however, that indicated some traditional classroom activities were compromised to accommodate the distance education environment. Students reported having difficulty paying attention to the instructor, and transmission site students also expressed greater feelings of alienation. Jones and Klopfenstein conclude that placing so much emphasis on students at remote sites might alienate students in the transmission site classroom. Achieving a balance between the transmission and reception site students presents the instructor with unique challenges even with the combination of compressed video transmission and Internet resources.

Chao (1999) notes that telecommunications networks can create environments that encourage students to function independently and think critically. One such application is the use of an asynchronous transfer model (ATM) network to provide simultaneous two-way video and audio transmission with high quality support of multimedia services. An example of this is the National Chung Chen University of Taiwan’s distance learning system, that uses real-time interactive distance teaching over an ATM network to distribute text, sound, video and pictures to sites on an ATM network created by the government of Taiwan. Chao obtained student feedback to help understand students’ perception of the system and improve its use. Findings from the survey indicated students in the broadcast classroom showed higher satisfaction than those in remote classrooms with the presentation of learning materials, the way instructors used the media, and the learning materials provided by the instructor. Additional results suggested that students in the broadcast classrooms had a more positive attitude towards the learning environment, with students at the remote sites dissatisfied with the quality of video and audio and with the quality of after-class and student-to-student interaction. Most students were satisfied with the interaction and feedback given by the instructor during class. A final result showed that more than half of the students thought that traditional learning was as effective as real-time interactive distance teaching. Chao concluded that while remote-site students showed higher percentages of dissatisfaction in some areas most students are willing to accept interactive distance teaching.

Compressed two-way audio and video over the Internet using CU-SeeMe, a low- cost Internet–based videoconferencing program, was used as a primary means of delivering course instruction for the first time in the fall of 1997 at Illinois State University. Hecht and Schoon (1999) reported on a master’s course in educational research delivered to an off-campus cohort by means of Internet-based videoconferencing. This method was chosen over other methods such as dedicated-line compressed video or instructor travel due to a lack of resources. Hecht and Schoon noted that instructors and students had to deal with frequent hardware and software failures during the first half of the course. Problems such as incompatible computer hardware, major loss of synchronization between audio and video, sometimes approaching twelve seconds, and interaction barriers due to audio difficulties were reported as significant barriers to course success. Hecht and Schoon note that while all of the students passed the course with similar grades to previous on-campus classes, an Internet-based videoconferencing delivery method required enormous amounts of time and technical expertise on the part of the instructor and school district staff, and a willingness on the part of the instructor and students to tolerate and recover from numerous glitches. Hecht and Schoon conclude that instructors and students need a large amount of time to become comfortable with the new technology and to plan for the unexpected. Included in this is the need to create multiple and repetitive modes of delivery in case one mode fails.

Kouki and Wright (1999) note that Internet-based videoconferencing technology is an important resource in a networked online educational environment. Video in support of audio and text based interactions can add value to a conference and significantly enhance communication. Kouki and Wright break videoconferencing software for use over the Internet into two types: (1) reflector-based conferencing, which was the first type of Internet videoconferencing software available; and (2) the Multicast Backbone, or Mbone, which uses multicasting to provide high quality videoconferences over the Internet. An example of reflector-based conferencing is CU-SeeMe, developed by Cornell University. Reflector-based conferencing consists of a client program and a server-like component called a reflector. Conferencing applications require continuous transmission bandwidth, which is achieved by using a transmission protocol called User Datagram Protocol (UDP) that gives priority to new data rather than correcting errors in what was previously sent. The reflector server is responsible for routing multiple streams of video, audio, and text during a conference to all participants concurrently. Without a reflector, only point-to-point conferences are possible. Kouki and Wright note that an advantage of reflector-based conferencing is that it opens multimedia conferencing to a wide audience by its compatibility with all the major desktop computer platforms. Another advantage is reflector-based conferencing’s low cost, which makes it affordable for students and institutions with limited resources. Reflector-based conferencing supports low bandwidth Internet connections as well faster connections such as a T1 connection. Reflector-based conferencing also can adjust the transmission rates to compensate for network congestion. Some disadvantages noted include a potential lack of security, as anyone with conferencing software can view an ongoing connection unless the system administrator takes special precautions. Communication delays between sites are a problem. Network congestion can lead to audio and video lags between sites. A point of special concern for individual users is bandwidth. Every open conferencing window consumes a portion of the bandwidth, so users must closely monitor the number of opened windows to avoid problems. Kouki and Wright provide two examples of reflector-based conferencing in education. The first is an undergraduate Cognitive Psychology course provided by the Virtual Summer School of the Open University in the United Kingdom, where students use CU-SeeMe software to participate in class discussions and attend guest lectures. The second example uses CU-SeeMe in an ethnography class at Stanford University. The instructor used CU-SeeMe to maintain his teaching and office hour schedule while traveling, and to give on-line workshops for students in remote classes. The second type of Internet-based videoconferencing is the MBONE, which stands for Multicast Backbone. The MBONE is a virtual network constructed on top of the existing Internet and facilitates live interaction and large-scale distribution of multimedia material. The MBONE has been primarily used for conducting multi-party videoconferences over the Internet. The MBONE works by eliminating the replication of video and audio data transmitted over the Internet, a technique called multicasting. This is different from a unicast method used by reflector servers where a server sends one copy of the video and audio data to each conference participant, which can require large amounts of bandwidth to handle the resulting high volume of data. Multicasting lowers the amount of actual data sent over the Internet, and places the data distribution burden on multicast-enabled Internet routers, which make copies as necessary. The MBONE thus transfers the bandwidth burden from the source of the videoconference to a network point nearer to each participant. This greatly increases efficiency. An example of an MBONE application cited by Kouki and Wright is NASA’s JASON project, which is an annual two-week expedition to remote areas of the world. The goal of the JASON project is to allow students to interact with scientists using interactive technologies. Advantages of the MBONE for telelearning include cost savings on videoconferences, and the capability of participating in multiple party videoconferences wherever a connection to the Internet can be found.

Research on Computer-Based Video in Education

In a qualitative study of the use of video in the classroom, Wise and Groom (1996) found that grades and grading did not change with the implementation of a multimedia system that delivered video and computer-enriched information to the classroom. The study was conducted using two Indiana school districts, which had implemented system-wide delivery of voice, video, and data from a centralized staging and switching office. However, teachers did observe that the use of various forms of video programs held the interest of most students better than instructor lecture alone. Wise and Groom also reported that bringing video material to the classroom brought a feeling and understanding of the real world into the more restricted setting of a traditional class. Students uniformly commented that classes conducted with video assisted instruction were more interesting and made the subject matter easier to learn. The study did find that students disliked working in project teams, due to internal competition, and a lack of quality in student and teacher produced material. Wise and Groom conclude that concentrating on grades as a measure of the effectiveness of learning may not be the best route. Non-subject matter skills such as in-depth understanding, the ability to generalize, the desire to continue learning as an enjoyable experience, and elevated student and faculty interest are positive effects of multimedia use in the classroom that can be built upon.

Cyberbuch is a Macintosh computer-based multimedia program whose goal is to improve the comprehension skills of students who are beginning to read German texts. Cyberbuch does this by first providing a contextualized preview of each text in the form of a QuickTime video clip, and then by providing hypermedia links, pictures, more QuickTime video clips, and definitions of words that encourage the learner to infer the meaning of unknown words or phrases. The program is self-paced and provides individualized options to accommodate different learning styles. The assessment of Cyberbuch by Chun and Plass (1994) entailed three separate areas: usability, learner behavior, and effects on language learning. The results of the usability test noted by Chun and Plass reveal pictures and movies were ranked by students as the most helpful, with text links of actual definitions rated the least helpful. The Cyberbuch user logs were examined next to determine if, for vocabulary quizzes, there was a correlation between which types of links were actually chosen and which were reported by students to be most helpful. This examination of learner behavior revealed a negative correlation for text links: when a text link was chosen, users did not find the text link helpful in more than 50% of the cases. On the other hand, when either pictures or QuickTime video clips were chosen during a vocabulary quiz, users did find those links helpful in 57% and 74% of the cases, respectively. The last assessment of the Cyberbuch program, effects on language learning for short-term vocabulary recall and overall reading comprehension, revealed a positive correlation between the type of link chosen during a vocabulary quiz and whether the word was learned correctly. Chun and Plass note that students showed a definite preference for the picture and QuickTime video links over the textual and audio links both in their responses to questionnaires about which types of links were most helpful and in terms of actual use of links while using the program. Chun and Plass conclude that while the QuickTime clips were of much lower quality compared to the physical clarity of textual and picture links, the video clips were found to be most useful overall, which suggested that the most important factor to the student appeared to be the type of link rather than the quality of the link.

A 1994 study by Ivers and Barron examined video and computer-based instruction (CBI) for instructing preservice teachers in the use of an electronic mail system. Research questions examined gains on a written achievement test, student perception of instruction, and near-transfer performance, which is the ability to actually use the knowledge learned. Ivers and Barron randomly assigned 24 volunteer students into two groups. One group viewed a video designed to demonstrate the use of FIRNMAIL, an electronic mail system provided free of charge to all educators in Florida. The other group received the same material through an interactive, computer-based tutorial. Both groups received a pre-test, followed by either video or computer-based instruction, a post-test, a FIRNMAIL assignment, and a perception questionnaire about the instruction. T-tests revealed that both groups made significant achievement gains in their knowledge of FIRNMAIL, although, no significant difference on mean achievement gains on the written post-test between video and CBI groups was found. Ivers and Barron reported a significant difference on students’ perception of instruction between students who were taught FIRNMAIL through a video presentation and students who were taught using an interactive, computer-based tutorial. The results indicate that students preferred to learn through CBI rather than through a video. The experiment also yielded a significant difference on the mean near-transfer performance between students who were taught using a video presentation and students who were taught using an interactive, computer-based tutorial. Ivers and Barron report that 80% of the students in the CBI group were successful in completing the FIRNMAIL tasks whereas only 45% of the video group successfully completed the FIRNMAIL tasks. Ivers and Barron conclude that the results support prior research that note that computer-based simulations were superior to other media, such as print, film, video, or lectures, for teaching and enhancing transfer.

In a study on students’ abilities to understand unfamiliar technical concepts through various media, Smith and Ransbottom (2000) focused on the availability and quality of digital video on educational outcomes. The experiment consisted of two projects, the first of which examined the impact of having an instructor present on degree of understanding of the content. The first experiment was broken down into six conditions, three of which used digital video, defined here as downloadable compressed video clips. Smith and Ransbottom reported no significant difference between conditions, which was attributed to the high variance in the results of all conditions, and the small sample size of each group. The second project in the experiment had the goal of providing an active student-centered environment, with students being able to demonstrate actual application of the concepts learned. Digital video was used in the context of the course of instruction, rather than stopping an activity to watch a video, as in project one. The second project was also broken down into six conditions, two of which used digital video as part of the treatment. Smith and Ransbottom found that the control group, which utilized a traditional classroom setting with an instructor interactively teaching the students, outperformed the other conditions in the experiment. This was attributed to a failure on the part of the experimental condition students of sufficiently managing the hour allotted for the treatment. Based on the results, Smith and Ransbottom concluded that video can complement text with a stimulating visual display which a blackboard cannot duplicate, provide facts and concepts, and allow learners to skip from segment to segment of a video program. Smith and Ransbottom also concluded that video cannot manage a student’s time or adjust its teaching style based on the body language of the student, which remains the role of the instructor.

Ellis and Childs (1999) examined the effectiveness of video as a learning tool in online multimedia modules. The videos examined were part of two interactive training modules of the Broadnet project, a partnership between the University of Wolverhampton, ICL, and Telewest Communications designed to foster regional economic regeneration through support of small and medium-sized enterprises. The videos were designed to teach legal concepts about workplace harassment and discrimination. Ellis and Childs noted that the design of the videos was affected by a combination of the educational and technical contexts within which they were to be viewed. Educationally, the narrative elements were designed to be viewed as short segments, as well as making sense as a single story. This was due to the use of the videos in three formats within the modules. The first format showed the student the entire story, while the second format showed the student short segments of a story to be used in assessment. The third format is described as a talking head where the lecturer simply speaks into the camera, outlining relevant content. Each video segment would be viewed within a Web page, which affected the technical design and shooting of the videos. The video must make sense in the context of the rest of the screen elements, and be viewable in a small area of the screen. Ellis and Childs report that the learners found the videos easy to navigate and control, and that the learners found the videos a useful tool for learning. This was explained as being a function of the problem-oriented nature of the video. The format that was reported as most useful was the format in which short clips are accompanied by questions. The talking head format was seen as monotonous. Ellis and Childs noted that the length of the video and the lack of interactivity contributed to the students’ reactions. Ellis and Childs concluded that video should be used to put the subject into its context of use, and that clips should be followed by questions to encourage active participation and to build on existing knowledge. Additionally, video clips should be used to elaborate on specific points and be of limited length.

Factors that Impact the Usability of Streaming Video

Usability is a term for being convenient and practicable for use (Merriam-Webster Online, 2000). Like any tool, streaming video must be usable before it can be effective. Streaming video is compressed video, and the compression potentially impacts the usability of the video. Audio quality is also another component of streaming video that must be considered to determine the usability of the material.

Factors Related to the Comprehension of Images

Streaming video, due to the technical requirements of transmission over limited bandwidth, normally implies a loss of resolution or image size from the original video source. D. J. Dwyer (1985) studied the effect of screen size and resolution on the legibility of graphics. Using three CRT screen sizes and four levels of resolution, D. J. Dwyer assessed the impact of changes in these variables on PC board chip locator performance. The results showed that screen size had a significant effect on response accuracy only when discriminability between test points was low, as on the pin side of a PC board, which has highly repetitious and densely packed elements. Response time, measured as the time it took the subject to locate and identify a test point chosen by random computer selection, was not significantly different at different screen sizes. No significant differences in response accuracy were found as a result of an increase in resolution. The results showed that subject response time varied significantly across resolution levels for component-side PC board graphics, while response times on the pin-side PC board graphics were equal for all resolution levels. D. J. Dwyer concluded that display size had no significant impact on the amount of time required to perform the locator task, and that level of resolution had no practical impact on either response accuracy or response time.

F. M. Dwyer, Jr. (1969) examined the effect of varying the amount of realistic detail in visual illustrations used to complement televised instruction. Subjects were divided intro groups consisting of a different visual treatment and an identical audio presentation describing the heart and its internal functioning. The visual presentations consisted of (1) no illustrations, names of facts and processes only, (2) simple line representations of the heart, (3) detailed, shaded drawings, (4) photographs of a heart model, and (5) realistic heart photographs. No significant differences were found in four criterion tests, which measured terminology, comprehension of the concepts presented, ability to identify numbered parts on a diagram of the heart, and total understanding of the concepts presented. The results did reveal a significant difference between groups on a criterion test that evaluated learning-specific locations of the various parts of the heart using drawings. F. M. Dwyer, Jr. compared the individual means of the five treatment groups on the drawing test and found that the students viewing the abstract line presentation and the detailed drawing presentation achieved significantly higher scores than did those students receiving the oral presentation without visuals. F. M. Dwyer, Jr. noted that students in each treatment group viewed their respective televised presentation for equal amounts of time, and students who viewed the more realistic types of visuals may not have had sufficient time to comprehend adequately the additional information contained in the visual illustrations presented to them. F. M. Dwyer, Jr, concluded that the data indicated that the instructional effectiveness of visual illustrations is a function of the type of learning task they are designed to complement.

Video images may also be classified as representational pictures. Representational pictures are those that share a physical resemblance with the thing or concept for which the picture stands. In a meta-analysis of instructional pictures and adult learning, Alesandrini (1984) noted that representational pictures can portray information directly or indirectly, and that representational pictures can be effective for facilitating adult learning. Alesandrini addressed whether or not the effectiveness of representational pictures is influenced by the level of abstractness or amount of detail in the image. Images can range in detail from simple line drawings to realistic color photographs. Several studies by Dwyer (1978), Gorman (1973), and Borg and Schuller (1979) conclude that simple line drawings are the most helpful to learners, while other studies by Myatt and Carter (1979) and Travers and Alvarado (1970) conclude that learners prefer viewing visuals that contain more detail.

Factors Related to Video Compression

Streaming video is by its nature digitized and compressed video. Compressed digital video is analog video that has been digitized, or converted from an analog signal to a digital signal (Anderson, 1982), and then mathematically scaled down to reduce redundant information and improve transmission efficiency (Ohanian, 1998, chap. 10). Video that is compressed is materially different from the original video signal. However, due to the nature of human vision, much of the information contained in a video signal can be discarded, and still result in a recognizable picture, which is how digital video compression works. Compression technology allows a full-size, full-frame video signal that requires nearly 170 megabits per second (Strachan, 1996), well beyond the capability of most computers and networks to process, to be scaled down to produce a recognizable picture capable of being delivered over the Internet through a 28.8 Kbps modem (Real Video, n.d.). This is an almost 6000-to-one reduction. At such extreme compression ratios, a logical question would be to ask what is the least amount of information transmitted for a video image to be recognizable. Ohanion (1998, chap. 3) noted that in the 1970s Bell Laboratories in Murray Hill, New Jersey, sought to ascertain how much information would have to be sent over a standard phone line for a picture phone image to be recognizable. The researchers came to the conclusion that if the intent of the image could be preserved the tendency of the human eye to blend contiguous areas and infer meaning would produce a recognizable image (Figure 1).

Keller, Staab and Stowe (1989) evaluated the quality of video sent over a two-way compressed video dedicated line conferencing system, using transmission rates of 56 Kbps and 384 Kbps. Three different video program sources consisting of still color graphics, a teleconference, and a section of a basketball game were selected to further examine effects of the different compression rates on video quality, and to attempt to determine the level of video quality compared to the uncompressed version, and what rates viewers would tolerate for a given application. Keller et al. found that at 56 Kbps most subjects found the still color graphics satisfactory, but would prefer not to watch the teleconference or basketball game, citing lack of sharpness, smoothness, and definition as major weaknesses.

Figure 1. The effects of different resolutions on an image. Higher compression results in a lower resolution (Ohanion, 1993).

At 384 Kbps, most subjects reported they would not watch either the teleconference or basketball game, even though the picture quality had improved. Subjects cited lack of color quality, sharpness, and clarity as reasons for not watching either program for long periods of time.

Factors Relating to Audio Quality

Audio is as important as visual imagery in evaluating streaming video technologies (Waggoner, 1998). The fidelity of the audio is the most critical component of media with regard to getting the message across (Reeves & Nass, as cited in King, Harnar, & Mayall, 1999). Audio can be anything from the spoken word to music or some combination thereof. When streamed, the audio must also be compressed. Although the bandwidth and information requirements for audio are less than for video, the human ear is much more sensitive to distortions or errors in the audio signal than the human eye is to errors in the video signal (Anderson, 1982). One such problem is asynchrony, or non-synchronization of audio and video. Verhagen (1994) pointed out that in audiovisual presentations, the visual channel and the audio channel are used simultaneously to convey messages. Hecht and Schoon (1999) noted in their evaluation of CU-SeeMe videoconferencing that non-synchronization of audio and video when using CU-SeeMe often resulted in a very confusing presentation for the students. The audio would sometimes lag seconds behind the video, stop, or even play ahead of the video signal.

King, Harner, and Mayall (1999) state that synchrony in media equals real life, and that asynchrony is unnatural. Synchrony is then a critical component of media. King et al. examined the effect on students of audio and video asynchrony. Using a T-1-based compressed video conferencing system, subjects were asked if they perceived asynchronous audio/video to have an effect on their performance. King et al. conclude that the findings suggest the asynchrony between the audio and video had no affect on student achievement as measured by final grades. The subjects’ self-reported attitude toward the asynchronous audio/video connection showed that the subjects did not regard this problem as serious or distracting, and their perception of their course achievement was not affected by the asynchrony.

Chapter Summary

Streaming video can be used in many of the same applications once reserved for broadcast television, such as story telling, modeling, and stimulating creative thinking. Like other forms of video, streaming video is not well suited for applications such as storage of information, presentation of complex ideas, and development of abstract thinking (Bates, 1984, p. 33). As streaming video overcomes barriers such as a lack of widespread high-speed Internet access, the amount of content available via streaming video stands to increase exponentially (Testa, 2000). As access increases, and streaming video grows in popularity and acceptance, it can be expected that the body of research on different aspects of streaming video will grow as well. The ability of streaming video to provide interactive video content to a user’s computer anywhere in the world opens up many possibilities for use in education.

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