Low cost home entertainment equipment that integrates a compact disc (CD) player with a personal computer offers great potential for bringing truly interactive multimedia into the student's home. This paper describes a project carried out by the School of Engineering and the Media Services Unit at the University of Southern Queensland, to present an engineering unit of study using Commodore CDTV. The process of scripting and producing an interactive multimedia program is discussed and the scripting documentation that has been developed is described. In addition to the primary educational content this CD contains several features that play important support roles. These are outlined and their educational role discussed.
"Remember what business we are in", the words of Rockley Miller, editor and publisher of Multimedia and Videodisc Monitor (in Sheehan, 1991), are a constant reminder that multimedia is a tool for communication rather than an end in itself. The exciting possibilities presented by multimedia systems and the myriad of equipment that usually accompanies it must not cloud our educational purpose. As educators, educational technologists and instructional designers we can embrace the thrill of the technology while remembering what business we are in.
As discussed by Johnson (1987) current investigations into the role of technology in learning and education draw the same conclusions as studies into mediated instruction over the past three decades, that is, it is the design and context of the instruction that is the vital factor in effecting the learning outcome.
Since 1976, the University of Southern Queensland has sought ways to meet the challenges presented by providing distance education. In the engineering field this has centred around effectively presenting the physical hardware of engineering, highlighting the underlying physical phenomena and developing the related mathematical models.
Because of the diverse spread of engineering students from remote mine sites to ships at sea, from 9.00 am to 5.00 pm workers to shift workers, a guiding principle in the search for effective delivery has been that the methods adopted must be available in the student's home and at a time that suits the individual student.
Over the years attempts have been made to improve delivery using 8 mm film, videotape and videodisc. Film, while interesting, led nowhere because of the relative difficulty of editing film with sound, the cost of multiple reproduction and students' limited access to projection facilities.
The widespread presence of VCRs in private homes overcame the access limitation. This medium proved relatively easy to edit and the cost of multiple reproduction was quite acceptable. Although videotape had the capacity to serve as the primary delivery mechanism, it was invariably used only as a supplement to conventional printed material. Also, despite the stop/start/replay features of the VCR the students tended to use the videotapes in a passive, linear way.
The School of Engineering produced a trial videodisc (Pemberton, Taylor & Tolman 1985) and while the medium itself allowed a considerable improvement in pedagogical method, the equipment was complicated, prone to interfacing problems and too expensive to be afforded by individual students.
Interactive CD technology appears to have overcome many of these limitations. Many of the phenomena treated in Engineering are dynamic and/or three dimensional; often these phenomena are very difficult to represent in the conventional print media, however it is anticipated that interactive CD has the capacity to do a much better job.
The old adage:
I hear and I forgetstill has firm foundations in learning theory. From Dale (1954) to recent cognitive science based studies (Taylor 1985: Clarke 1992) the real life experience is a vital component of empirical learning. The external engineering student is generally surrounded by this experience and the educational challenge is to associate the fundamental physical phenomenon and mathematics with that reality.
I see and I remember
I do and I understand
Another aspect is that for many external students the breadth of their real life experiences is limited to the demands of their particular job, the educational task is to broaden their experience in areas that would otherwise be unavailable.
authoring software were challenged to deliver the goods. This approach released any inhibitions the instructional designer and content expert may have had in their vision of the potential of the medium.
The next step, developing a concept map of the factors involved in reaching the objectives, serves several purposes. First, it establishes lateral thought processes, helping to break down the hierarchical structures that are usually embedded in traditional approaches to course delivery. Second, it can result in an overview based on quite abstract concepts, which in turn generates fresh ideas. Third, it provides a visual picture for identifying relationships between the components. Concept mapping is essential for establishing the style of thinking conducive to designing for the multi-layered, multi-directional characteristics of interactive multimedia.
The steps that follow consist of identifying the content, establishing content clusters, developing a content map and identifying interactivity links. These steps are generally commenced in this order but they do not finish before the next one begins.
Identifying the content will start to trigger ideas for the audio script, specification of graphics, identification of possible interactivity paths and identification of desired accessory features. As the content clusters, map and links are established these concrete aspects will continue to grow so the instructional design and development process takes on a spiralling character.
Features were identified that the student would need to access from any point in the course. These included, glossaries of terms and symbols, banks of laboratory demonstrations, field examples and data such as mathematical formulae. Engineering expert systems and simulations were included, a calculator program and word processing program supporting a notebook facility and all of the conventional printed external notes were included.
A course stream option enables the student to select the appropriate level of study to be followed for example, undergraduate diploma or degree or post graduate diploma. A language option provides additional support for international students and offers potential for overseas marketing.
No hard barriers have been included in any stream, only guide posts, so the student is free to explore the learning material in the way best suited to the individual's interests and needs.
All of the information stored on the CD presents a rich collection of resources that can also be used in the traditional lecture setting.
Specific content scripting could then begin for each cluster, working through the levels and branches of information. This is aided by the use of a script proforma which provides for screen graphic requirements, audio, hot spot identification, video segments and programming pathway identification.
A content map can be developed while scripting is in progress. This is usually done in a draft format to allow for the numerous changes that take place as the script is refined. As the content map shows every screen with its unique number, graph paper makes the task a little easier. The content map makes it easier for the programmer to translate the content arrangement into the computer program.
The latest version of the script proforma includes areas for recording the specific interactivity pathways from buttons and hot spots. There are also areas for the audio script, description of video segments, common usage identification and comments to the programmer.
Normal high fidelity audio requires the sound track being sampled 44,000 times per second and recording over the frequency range 20-20,000 Hz. By sampling only 12,000 times per second and recording only over the 100-5,000 Hz frequency range the audio capacity of the disc can be extended to 17 hours.
Conventional television presents images at a rate of 25 frames per second and each frame has potentially 16,000,000 colours. By restricting each frame to 4,096 colours, reducing the frame rate to 14 frames per second, and then not recording the full frame but only the changes in image from the previous frame, and physically compressing each image to 1/4 screen, the video capacity can be increased to 65 minutes.
This general philosophy runs throughout the CD. In computer graphics and animations, as with the audio and video, the minimum resolution and number of colours are a compromise between storage limitations, processing speed and definition of image.
It follows that only minimal modification of the graphic images is needed to match the different languages. The mathematical symbols and conventions are the same and it is quite acceptable that on screen text be in English.
This data bank can be accessed at any time simply by clicking on the Data Button. Any data selected can be transferred directly back to where the student was working and incorporated into that activity. The data can even be incorporated into the Notebook or the Calculator.
For this reason a glossary of words and symbols has been incorporated on the disc. It can be accessed in two ways:
This compendium has two major intended uses in addition to the above. First, it can be used by a lecturer/tutor to support and supplement a conventional face to face class. Second, it can be accessed randomly to build up individualised tests.
The students can display this as text on screen or take off a hard copy as they wish. It presently costs about $38 per student unit to print each set of study materials and a further $9 to mail them. The comparable costs for a CD are $1.40 and 85 cents. It is expected that this financial incentive will lead to the early demise of the conventional study materials once CDTV and its kindred devices are commonly available in Australian homes.
To this end controls and functions that had to be available at all times were identified. Beside the A and B buttons provided on the remote hand control unit, four program control functions and five facility functions were identified.
The design and operation of these controls had to be consistent. The major control buttons always have the same appearance and occur at the same locations on the screen. Hot words and symbols are always identified in the same way. The colours, text style and function symbols must also be consistent and sub-topic screens are always distinguished from topic screens in the same way.
The selection of colours for the generic screen design had to take into account compression and disc storage space requirements.
As this pilot CD project was based on the use of the home television, screen design had to also be concerned with the readability of text and the resulting limited number of characters possible on the screen.
A consistency of approach was necessary for the presentation of 1/4 screen pseudo video, metamorphosis and graphic techniques. Another operational convention that was adopted was a zoom feature. Clicking on a wide shot illustration would result in progressive closer shots.
With all of these issues in mind, the general aesthetic considerations for screen design were put into the hands of a graphic designer.
The largest feature on the form is the graphic box. It is distinguished by a 29 x 17 grid. Because CDTV displays on a conventional TV, on screen graphics are limited to 29 characters across and 17 lines down the screen. Beyond these limits on screen text becomes difficult to read. This grid assists the writer to design screens within these limits.
The extreme two right hand columns of the screen are occupied by button symbols. These are the buttons that control the routine interactivity and give access to the facilities incorporated in the CD.
Immediately to the right of these buttons is a further column labelled "Branch to". This is used to specify the frame that the program will move to if the corresponding button is clicked. Note that the top button, labelled B, is outside the limits of the screen. This is the B button on the CDTV hand controller.
The box at the bottom of the graphic box contains space for recording the storage location, frame number and keywords. Every asset, be it a computer graphic, an animation, a video still, a video sequence or even an audio sentence has its own unique identifier, its frame number. It is through this identifier that the asset is linked to the overall program.
The storage location reference is used simply to record where the original asset is stored, for example, video tape number and time code or computer disk and file name.
This box also contains space for keywords. The various assets can be accessed independently through a keyword search facility called a compendium of resources. It is here that the writer specifies the keyword descriptors for each asset.
It is not unusual for the one segment of narration/sound effect to be used in more than one place in the program. In such cases only the unique identifier is entered here.
It has been a valuable exercise. The team has developed competence in all of the relevant areas. Most importantly the equipment has been able to deliver everything asked of it so far. At this stage it is the imagination of the authors, rather than anything else, that is the limiting factor.
The next step of the project is to produce a CD that contains one whole unit of study and trial it with students. That stage will also evaluate the costs of producing the CD.
Dale, E. (1954). Audio-Visual Methods in Teaching. New York: Holt, Rinehart and Winston.
Johnson, J. (1987). Electronic Learning From Audiotape to Videodisc. New Jersey: Lawrence Erlbaum Associates.
Pemberton, P. F., Taylor, J. C. & Tolman, M. (1985). Interactive Videodisc and Student Control of Learning. Paper presented at CALITE '85, Melbourne.
Taylor, J. C. & Evans, G. (1985). The Architecture of Human Information Processing: Empirical Evidence. Instructional Science, 13, 347-359.
|Authors: Lesley Richardson started her career as a secondary art teacher, then worked in TAFE Victoria as an Educational Technologist/Instructional Designer. She worked in Canberra, including a period as Head, Educational Media Department at Woden TAFE College. In 1986, she won a Commonwealth Overseas Study Award which took her to Canada and the UK to investigate developments in the use of technology in education and training delivery. She took up her present position at the University of Southern Queensland in 1987 as Head, Media Services Unit. She can be contacted at: Media Services Unit, University of Southern Queensland, Post Office Darling Heights, Toowoomba 4350
Tom Duncan began his career with TVT6 in Hobart and subsequently with ATVO in Melbourne. In 1971, he returned to Hobart to work with the ABC. He moved to Queensland in 1978, working first with TVQO and later for a private production house, Video Image Production. In 1985, Tom joined DDIAE (now University of Southern Queensland) as Technologist in Media Services. During his work at USQ, he has worked extensively on technology and promotional material. He uses an Amiga 3000 Computer for all Graphic related material and writes software programs for the Corporate Television Industry.
Please cite as: Richardson, L. and Duncan, T. (1992). The interactive CD - learning and/or entertainment? In J. G. Hedberg and J. Steele (eds), Educational Technology for the Clever Country: Selected papers from EdTech'92, 164-174. Canberra: AJET Publications.http://www.aset.org.au/confs/edtech92/richardson.html