|
|
|
|
|
|
|
When considering hypertext and hypermedia it was noted that the two terms are interchanged. Unfortunately, the same can also be said for hypermedia and multimedia. Several years ago, there was a distinct difference in definition between the two of them with hypermedia being a program which was self contained so that the associated media were displayed on the computer, while multimedia referred to a presentation where a computer was used to control a peripheral device which was normally a videodisc player. In this case, the information from the videodisc was displayed on a high resolution video monitor and not the computer screen. The change in definition can be illustrated by John Sculley, the then CEO of Apple Computers, who wrote a forward in three editions of Goodman's Complete HyperCard Handbook. In the second edition (October, 1988) Sculley writes: Hypermedia. It's a new word for most of us. Yet this term and its definition will become increasingly important the more we rely on personal computers to store, manage, and retrieve information (1988, xvii). However, in the third edition (August 1990), Sculley makes no reference at all to Hypermedia, rather he says: In parallel with HyperCard's ready accessibility came increased interest in multimedia. HyperCard quickly became the software platform of choice for creative artists who mix on-screen animation, digitized and pre-recorded compact disc audio, and live motion video into richly woven experiences for education and personal enrichment (1990, xix). This merging of the two terms is further illustrated by Dede who in an article entitled The Future of Multimedia: Bridging to Virtual Worlds, writes extensively about hypermedia and, in fact, describes it as being "the associative, nonlinear interconnection of multimedia materials" (1992, 55). Ralston (1991, 58 cited in Galbreath 1992, 15) suggests that the term hypermedia should be used instead of multimedia, which tends to go against the current trend. He justifies this by arguing that: The term Multi-media is redundant; media is already plural in character. Moreover, Multimedia has previously been widely applied as describing a far different entertainment industry. ... Using Hypermedia instead in microcomputer discussions today is a better choice. It correctly connotes its interactive desktop computer driven character. This properly distinguishes Hypermedia from those song-and-dance, Multimedia concerts and shows of the 1960s that gave the latter its earlier meaning. Galbreath (1992, 15) claims that the definition of multimedia will vary from person to person. To substantiate this claim, he quotes definitions given by a variety of people: ... to qualify for the title multimedia, an application needs only to incorporate two or more of the following: still or animated graphics, still or motion video, audio, or text and numerical data (Berk and Devlin 1990, 15 cited by Galbreath 1992, 15). The situation in regards to multimedia is further confused by the fact that there are two distinct flavours of it, presentation multimedia and interactive multimedia. Presentation multimedia is used mainly by the business world. The computer is used to control various media such as sound, graphics, animation and video to produce a presentation which is then recorded on video tape for use as promotional material. The main advantage of this over preparing such materials by conventional means is that it does not necessarily require specialist staff to produce them and so is much cheaper. This is illustrated by the production of computer generated animated films where the films can be produced at a fraction of the cost of normal animation where teams of highly specialised animators are involved. While the use of such multimedia is usually confined to the business sector, some see it as having a role in education, not as a means of instruction, but rather as a way of students presenting information that they have studied. The main proponent of this use of multimedia is Fred D'Ignazio. D'Ignazio writes: Imagine a classroom in which students take on the role of multimedia authors - creating radio shows, movies, books, magazines, advertisements, and slide shows about fractions, prefixes, Spanish verbs, Helen Keller, or any of a variety of other curriculum topics. Imagine productions so fresh and unusual that they are shown to the entire class, to other classes, to the PTA and the local school board; or displayed (and catalogued) in the school library and aired on local cable TV. And, if that doesn't move you, imagine a setting in which the technology involved in such productions - those finicky, malfunctioning machines that seem perversely designed to drive teachers into premature retirement - is managed primarily by students themselves (1989, 22). He argues that if teachers consider multimedia to be "new commercial programs that incorporate computer software with videodisc" (the definition of multimedia at the time) then they should reconsider as some teachers are taking a different approach to multimedia by "placing the technology in the hands of the students and allowing them to take on the active role of multimedia producers" (1989, 22-23). Doing this, he states, gives the students an amazing sense of pride. D'Ignazio (1989, 209; 1989a, 37) suggests that many teachers would be put off from considering this use of multimedia due to the perceived expense of the equipment involved. He advocates, however, the creation of multimedia publishing centres using scavenged equipment such as a video camera, audio cassette player, musical keyboard, television set, computer and video cassette recorder. Using this approach, he claims that such publishing centres could be created comparatively cheaply. The effective use of student based materials is also described by Bransford et. al. (1990, 131-132). In their work students produced computer-controlled videodisc presentations. They found that this was very motivating because, as the video material was professionally produced, this gave their presentation a very professional appearance, and: This increases the interest of the audience, which in turn increases the quality of their feedback with respect to product quality. Students therefore take a great deal of interest in creating products that are of high quality. The type of multimedia most commonly used in education is interactive multimedia. The user, as the name suggests, can interact with this so that information can be accessed in a non-linear fashion. This term can be further sub-divided according to the hardware platform that supports it. Galbreath identified four such platforms all of which are optical discs of one form or another. |
|
|
|
|
Interactive Video |
|
|
Videodisc is the original optical disc and has been available for more than 10 years (Galbreath 1992, 16). They are 12 inches in diameter and store information in analogue form. The disks are double sided and can hold 30 minutes of video on each side. This video is held in 54,000 individual frames per side, each one of which is individually addressed. This means that, as well as accessing all the material in a linear fashion, each frame can be directly accessed. In addition, as each frame is a separate entity, the video can be viewed in fast or slow motion or in perfect freeze frame mode (Bransford et al. 1990, 125). Another great advantage of optical discs in general compared with a medium such as video tape, is that there is no physical contact between the 'read' head and the disc. This means that a still frame can be maintained for some considerable time without any danger of damaging the disc. Videodiscs have three levels of interactivity. At level I a videodisc is played on a videodisc player with little user control. In this mode, a videodisc would be used for replaying a film in much the same manner as it would be played by a VCR. Level II uses a small hand-held device which is used to give a degree of interactivity, while at level III, a computer is in control of the videodisc player and it is at this level at which interactive multimedia becomes a reality (Galbreath 1992, 16). There are two different forms of interactive videodisc systems. In the first, the video from the disc is displayed on a separate television screen. While this is the cheapest form, extra cost is incurred through the necessity to purchase a high resolution monitor. Also, there is no real focus to the presentation as the text appears on the computer screen and the video on the monitor. The second type uses a video card in the computer to which the videodisc player is attached. This allows the video image to be viewed directly on the computer screen and to be merged with the normal computer output (Galbreath 1992, 16). Galbreath (1992, 16) notes that it appeared for some time that interactive videodisc was losing it popularity but it now appears to be making a come back and, to support this claim, states that in 1990 the Texas School Board decided to adopt a videodisc based curriculum as a potential replacement for textbooks. He also notes that several companies have produced compression systems which greatly increase the capacity of these discs. This leads him to the conclusion that "Without question, interactive videodisc is a viable multimedia delivery platform, and one that will likely be used throughout the 1990s". |
|
|
|
|
CD-ROM |
|
|
Compact Disc Read Only Memory (CD-ROM) is based on the same technology as the Compact Discs used for storing and replaying music. They have been available since 1985 but it is only recently that they have started to make a major impact on the market. There are several reason for this. While today's CD-ROM players access information at a slower rate than can be achieved from a floppy disc, this is considerably faster than previous models. The price of players has also dropped considerably; over the past 18 months, the educational price of Apple CD-ROM players has decreased from approximately $1,500 to $750. In addition, companies such as Apple have deliberately set out to promote CD-ROM technology and, in fact, some of Apple's new range of Macintosh computers are equipped with in-built CD-ROM players. Finally, this increase in the number of players in the market place has made the production of CD-ROM based software a much more viable proposition for manufacturers. CD-ROMs are 4.72 inches in diameter and hold approximately 650 megabytes of data. As indicated previously, while this appears to be a large storage capacity, when it comes to storing video it is woefully inadequate. Standard (US) television runs at 30 frames per second and so to convert one analogue frame to digital format requires about 600 to 750 kilobytes of storage. This means that a CD-ROM can only store about 30 seconds of high quality, uncompressed, full-motion video. Manufacturers realised that, to make CD-ROM an efficient storage medium for video, compression techniques would have to be devised. The first of these was Digital Video Interactive or DVI (Galbreath 1992, 16). |
|
|
|
|
Digital Video Interactive |
|
|
The essence of DVI is a set of compression algorithms held in hardware that can reduce the storage requirements of one video frame to less than 5 kilobytes which enables a CD-ROM to hold more than an hour of video. Since its creation in 1984, DVI has not made a great impression on the education market but the technology has now been acquired by Intel (who manufacture the range of central processing units used in MS-DOS computers) and IBM, and Intel claim that DVI technology will be built into the microprocessor itself and so will become a standard feature of the personal computer by the year 2000. In view of this it can be assumed that this technology has a large potential in the area of educational multimedia (Galbreath 1992, 17-18). |
|
|
|
|
Compact Disc-Interactive |
|
|
Unlike the other systems described so far, CDI, which was developed by Philips and Sony in 1986, is not an add-on to a personal computer, instead it is a stand alone unit which is designed to connect to a home television set. Its primary market is home entertainment, and this is reflected by the fact that it is capable of playing audio CDs as well as CDI discs. Due to its low cost, however, it may well make an impact on the classrooms of the future (Galbreath 1992, 18). |
|
|
|
|
Commodore Dynamic Total Vision |
|
|
Commodore Dynamic Total Vision (CDTV) is a similar system to CDI in that it is a stand alone unit that plugs into a television set and is capable of playing audio CDs. It is based around the technology of the Amiga computer and gives high quality sound and graphics. As yet it does not support full-motion video but this facility is under development. CDTV is interactive with user-input coming from a hand held remote control. This system, while being aimed primarily at the home market, will find its way into schools as a low cost multimedia platform (Galbreath 1992, 18). |
|
|
|
|
Compact Disc-Read Only Memory Extended Architecture |
|
|
Compact Disc-Read Only Memory Extended Architecture (CD-ROM XA) was developed by Microsoft, Sony and Philips and released in 1988. It is designed to hold digital and still images but has been demonstrated to provide limited amounts of video. Like a standard CD-ROM player, the CD-ROM XA player is connected to a personal computer (Galbreath 1992, 18). |
|
|
|
|
Laserdisc-Read Only Memory |
|
|
Laserdisc-Read Only Memory (LD-ROM) was developed by Pioneer in 1989. It is designed to combine the analogue technology of the videodisc with the digital technology of CD-ROM. It can hold 30 minutes of video per side (the same as standard videodiscs) plus 270 megabytes of digital information. Development is under way to allow the full contents of a 12 inch videodisc to be stored digitally (Galbreath 1992, 18).
When surveying these multimedia platforms, the surprising thing is their slow acceptance. For example, CD-ROM technology has been available for nearly eight years, but is only now making an impact on the market. The main reason for this is that a combination of hardware and software is required. Consumers are reluctant to purchase hardware if there is little software available, and software houses are reluctant to spend the large sums necessary to produce multimedia presentations if there is only a small market. In view of this, it can be argued that CD-ROM is the technology that will make the greatest impact as a medium for storing multimedia in the near future as it is the one which is currently being promoted by the computer industry as a whole. It should be noted that, while much of the discussion of multimedia centres around the platform that supports it, this is only the storage medium. The main component of multimedia is the software; the only contributing factor that the storage medium makes is to remove the storage restrictions imposed by other storage media thus allowing more sound, graphics and video to be used. While these optical disks enable the software to be distributed, they are of no help to the developer as they are 'write-only' media. Fortunately, various forms of 'read and write' large capacity storage media are being developed and these allow the software to be stored during its production. Strangely, no references to the design principles necessary for the production of successful educational multimedia were discovered. Perhaps it is assumed that those designed for hypermedia are sufficient. As most writers suggest that hypertext/hypermedia/multimedia take a constructivist approach to learning, it was interesting to note a 1992 article by Milheim from Penn State setting out the criteria for a university multimedia design curriculum stating that the instructional design component should be based on the work of people who take a behaviourist stance. Old habits die hard! |
|
Footnotes |
|
|
The trend towards the use of Multimedia is demonstrated by the projects that received funding for the 1993 National Teaching Development Grants provided by the Committee for the Advancement of University Teaching. In all some 88 projects were funded and of these 41 (46.6%) had 'computer' in their title and 18 (20.6%) used the term 'Multimedia' with none using 'Hypermedia'. It is interesting to note that 35.7% of all the funded applications from West Australia contained 'Multimedia'. Return |
|
|
This is my personal term for it as I have not come across any title other than multimedia for it. Return |
|
|
Fred D'Ignazio is President of Multimedia Classrooms, Inc. ... He conducts teacher workshops all over the U.S. and Canada, and is a national leader in the areas of multimedia, merging technologies, and cooperative learning (Classroom Learning, October, 1989, 211). Return |
|
|
Apple CD-ROM discs have a capacity of 656 MB in Mode 1 and 748 MB in Mode 2 (AppleCD 150 User's Guide 1992,33). Return |
|
    |
|
|
Author: Tony Brown Created: 25.6.97 © The University of New England, NSW, Australia |
