The three features of the computer technology that are relevant to the presentation phase of the instructional cycle are multimedia, easy access and timing control. We will now examine the application of these three features in turn.
Multimedia presentation, which render CALL programs far superior to conventional textbooks, have been used to various extent in all CALL programs . All programs mentioned in this paper feature digital audio. Half of the programs (ABC, HC, PIC, SC, WL) feature animated demonstration of character writing. ABC, PIC use animation and PM uses movie clips to demonstrate the production of speech sounds. WL uses still graphics to show character shapes at various historical time periods. TRS depends solely on graphics to convey meanings. But despite the potential presentational advantages of CALL programs, the basic format of presentation remains similar to conventional textbooks. In most of the programs referred to in this paper, the initial presentation is still done mostly with the written form, either in romanization or in Chinese script. Meanings are also mostly conveyed with English glosses.
Why is it a problem to present with the written form? Most importantly, speech is primary while writing is secondary. The question is not whether written representation should be used but when to introduce the written form relative to the spoken form. With a human teacher, the spoken form can be introduced before the written form; in a conventional textbook, the spoken form cannot be presented without the written form. But there is no need for CALL programs to put up with the limitations of the print medium. As programs already provide audio along with the written form, it is then just as easy to present the spoken form without the written form. One program that does allow audio-first presentation is TRS, which clearly separates text and voice and offers all the possible combinations, such as text with voice, text without voice and voice without text. The second problem with pure written presentation is the assumption of literacy, which cannot always be made. So if someone does not know romanization or characters, it does not mean that s/he does not know how to speak, and vice versa. This realization can be especially important in a testing situation, where the validity of the test can be compromised by a mixing of skills.
The problem with the exclusive use of English glosses to convey meaning is that it is indirect as well as possibly misleading. Admittedly, CALL programs are not particularly worse than conventional textbooks, which do the same thing. But CALL programs can have many more resources than a conventional textbook. A more direct mode of presentation, especially for concrete vocabulary, is eminently possible. An early program developed by Yao and Mowry, modestly named Miss Li and Mr. Wang, uses simple animation to teach the action verbs for dressing and undressing8. Of the programs mentioned in this paper, TRS's conveying of meanings is exclusively with pictures. PIC uses pictures to convey meanings in both the flashcard stack and the interactive vocabulary builder.
The easy access allowed by the computer has a number of desirable consequences for presentation. It allows instant retrieval of help for pronunciation and comprehension, with the simple 'when in doubt, click' format. We can thus avoid the pre-teaching of vocabulary, which is out of context and can miss the target altogether due to individual differences in learner backgrounds. The easy availability of help also enables, paradoxically, the option of hiding the help initially, hence making it possible for the learner to challenge themselves. Furthermore, since every grammatical and vocabulary item in a lesson can be linked to a shared pool of glosses and explanations, an extreme form of redundancy and recycling is possible. This redundancy and recycling further encourages learner-choice in lesson selection and sequencing.
The programs reviewed here make use of the easy access feature to various extents. For example, while ABC, HC, PIC and SC opt to present part or whole of a dialog on the screen, CX presents it one sentence at a time, in a sequential fashion. Obviously, it is harder for a CX user to locate a particular word or sentence. While most programs do not pre-teach vocabulary, HC presents the vocabulary separately, before the dialogs, thus taking the vocabulary out of context and making it hard to provide help for every linguistic item in the dialogs. While SC, ABC and PIC provide on-line vocabulary and grammar explanation only when requested, HC uses such optional on-line help for grammar only and opts to provide glosses to words and sentences obligatorily, thus missing an opportunity to challenge the learner. Programs also differ in exploiting the maximum redundancy the easy access feature makes possible. With no graded lessons of its own, WL has to provide instant lookup to every word and character. Though their vocabulary help is a bit hard to use, ABC and PIC also provide glosses for every character and word in the text. SC , however, provides vocabulary help for only pre-determined new words and expressions. By having pre-determined vocabulary for every lesson, HC also does not provide maximum redundancy.
Timing, impossible to do in a printed textbook, has been used in some CALL programs. Users of CCT can opt to incorporate delay of different amount in the presentation of audio, text or characters. It too uses user-selectable time limit in its tests. In its vocabulary drills, HC uses delay in presenting the audio or the written form. The use of delay introduces the element of challenge without actually turning it into a test.