28.4 Audio-Tutorials

There are few cases of the large-scale, systematic application of audio technology to instruction. One interesting and extensive implementation of audio for instructional purposes is Postlethwaite's "audio-tutorial instruction" (ATI). This approach, which has been widely reported (Postlethwaite, 1970, 1972, 1978, 1980; Svoboda, 1978; Button, 1991), is more a complete instructional system than just an application of audio, but its long history and wide application make it an important source of information. Because of its well-elaborated structure, I will de scribe it in depth.

ATI began almost by accident in 1961 at Purdue University (Postlethwaite, Novak & Murray, 1972), when Postlethwaite was attempting to provide supplementary materials for weaker students in freshman botany. Simple lecture material was made available on a self-study basis through the audiovisual department. During the semester, these tapes evolved into programmed experiences that directed the students' attention to sections of the textbook, pictures, and diagrams, as well as live plants. Eventually experiments were added, and the entire week's study could be covered without attending any formal sessions. Student reaction was favorable, so in 1961-62, an experimental section of 36 students was taught entirely by audio-tutorial. Results on the conventional exam showed that the experimental group performed as well as the regular students. Interviews with the students led to the creation of a completely restructured course.

In designing the new course, Postlethwaite studiously avoided using words like lecture, recitation, and laboratory, which he felt connoted formality and passivity. The new course consisted of "independent study sessions," "general assembly sessions," "small assembly sessions," which included "integrated quiz sessions," and other small assembly sessions. Other additional activities were sometimes included.

The independent study session is the heart of Postlethwaite's system. Students would check into a special learning center with 36 booths equipped with tape recorders, movie projectors, and other materials. Armed with a list of behavioral objectives and the tape, the student would proceed through a series of activities. The tape was not a lecture. Rather it was a land of programmed guide that would direct the student's attention to certain parts of the book or other materials. The tape acted as a land of tutor, suggesting activities and pointing out important information. The student would perform experiments, read short segments of text, fill in diagrams or charts, view films, or examine specimens. The- program could be interrupted at any time, and students could talk with other students or instructors if they were confused. Students could also omit activities if they felt they understood the content.

The general assembly sessions were held at the end of the week and were intended to support activities that could not be performed at the individual session, such as exams, guest lecturers, and long films.

The integrated quiz sessions had an especially interesting structure. About eight students would be seated around a table covered with items drawn from that week's objectives. On the assumption that the best way to learn about something is to teach it, the students would be asked to discuss an item chosen at random. The student would first name the object, relate it to the behavioral objective, and then explain or demonstrate the object to the class. Once all students had completed this graded, oral quiz, a 20-point written quiz was given.

Another interesting feature was that although a small project involving the collection and analysis of data was compulsory for all students, any students desiring a grade of "A" were required to complete a second, original project.

It appears that Postlethwaite was acutely aware that an audiotape-mediated course might take on the appearance of impersonality. To avoid this, several measures were taken. The tapes were made with an informal, conversational quality. The instructors in the learning center were apparently told to maintain a pleasant personal manner. The senior instructor spent 3 hours per week in the small quiz sessions, meeting with about 48 students. Another 3 hours were spent informally visiting the learning center. He also held a weekly coffee hour to which all students were invited. Finally, he held an open house (for 600 students!) at his home once a semester. Postlethwaite considered this emphasis on personal contact and a well-structured sequence of learning events to be the essential ingredients of ATI.

As a result of his experience, Postlethwaite and his colleagues (Postlethwaite, Novak & Murray, 1972) were able to provide guidelines for the production of audio-tutorial lessons: First, they emphasized the importance of behavioral objectives. All course objectives should be listed first and test questions should be written concurrently, if possible. Second, you should list on cards all activities needed to reach the objectives. This should include the medium of presentation of the activity. Third, you assign the activities to the different kinds of sessions, as appropriate. Finally, you arrange the activities in a proper sequence, taking into account prerequisite knowledge. Once this is completed, the Program tapes can be produced. Postlethwaite also provided guidelines for this step: First, assemble the required materials for an activity and make a demo tape. It is helpful to have an average student present as you do this, because the student's questions will trigger necessary elaborations and will give the tape a true tutorial feeling. Next, transcribe the tape and edit it critically. This eliminates redundancy and imprecision. Finally, make the final tape from the edited script, which may have emphasis or other helpful markings added.

In the production of the actual tape, Postlethwaite gave the following guidelines: First, with regard to voice, use a conversational tone, speaking clearly and cheerfully. Vary your tone frequently. Speak rapidly. Avoid "uh's" and other annoying speech habits. Second, concerning the content, aim for critical thinking. Do not lecture. Do not read the directions. Involve the students by directing their attention to actual things. Keep things simple but don't repeat, because the students can play back the tape if necessary. Proceed from the known to the unknown. Keep the lesson as short as possible, but be sure to clarify critical points. A variety of voices and sounds can increase realism. Finally, with regard to the mechanics, adjust the volume and tone to an appropriate level. Keep a constant distance from the microphone. To make corrections, find a natural pause in the conversation and begin there. Signal the student to stop the tape while performing an activity. A sound effect is better here than a spoken instruction that will have to be repeated many times.

Since a good part of design is avoiding errors, Postlethwaite and his colleagues listed some pitfalls associated with ATI. Since these pitfalls may be encountered with any mediated course, they are worth repeating. First, they list problems associated with the structure of ATI. One problem may be the lack of specific objectives. The sequencing of instructional events requires the clear specification of objectives. Also, ATI cannot be a lecture-on-tape. This is certain to be more boring than the original. Visuals that are too complex, lengthy, or irrelevant can detract from learning. Study materials that are unnecessary to the objectives are wasteful of time and money. Auxiliary experiences outside the learning center can be very valuable, but discussion and evaluative feedback are essential. Synchronization of mediated lessons with actual activities is difficult to predict and requires trial-and errors adjustment.

There are also psychological issues associated with ATI. First, the structure of the course is crucial to learning. Postlethwaite recommended Ausubel's subsuming structures, but augmented this where appropriate. Equally important, substructures of the course should also be paced and subsumed appropriately. This is very difficult to predict in advance, and almost always requires adjustment as a result of student feedback. Because older students have extensive vocabularies, direct experience is not always necessary, but when new concepts are being introduced, direct experience supports meaningful learning. Student feedback is essential to determining whether instruction is effective. On the other hand, feedback on small objectives may not be useful because it does not reflect the larger structure of the course, which is intended to clarify difficult concepts by repeated experiences. Finally, affective factors are easy to over- or underestimate. However, they cannot be ignored. Individualized audio-tutorial instruction capitalizes on the students' desire to be in control of learning, but it does not satisfy their social drives. For this reason, group work needs to be included.

In summary, in spite of the age of the Postlethwaite book (1972), it can still be recommended as a guide for the individualization of courses, especially where they are to be audiomediated.

Despite the widespread use of ATI, evaluation studies are not numerous. The common results reported (e.g., Postlethwaite, Novak & Murray, 1972) indicate that it is as good as conventional instruction with positive attitudinal ratings. However, there are a few reports of an advantage for ATI. For example, in Huppert and Lazarowitz (1990), 15 students used an ATI unit to learn cell biology. Standard classroom lab techniques were used with 65 others. Although the control group had significantly higher pretest scores, posttest scores were equal, indicating greater gains by the ATI group Also, higher-ability students tended to score higher with ATI. In another study, Carter and Cooney (1983) reported that undergraduates exposed to modified ATI in a statistics class showed a significant increase in performance, even under low-motivational conditions. Low motivation was indicated by the fact that students generally expressed the belief that the course was irrelevant to their career. Despite some methodological shortcomings, Carter and Cooney's effect size was 1.8 standard deviations, an astonishing gain under the circumstances. However, this gain was against a control group that received no instruction. Thus, these numbers reflect the effectiveness of ATI, not its superiority to conventional instruction.

The most comprehensive review of ATI is Kulik, Kulik, and Cohen (1979). This meta-analysis of 48 reports of ATI found a small but significant achievement effect for ATI over conventional instruction. However, ATI had little effect on course evaluations or withdrawal rates. Also, aptitude and achievement correlated highly, indicating that ATI does not have a leveling effect as might have been expected with such a self-directed, self-paced approach. Thus, the best available evidence seems to indicate that ATI does have a small positive effect on achievement, but given the fact that it does not seem to have other advantages over conventional instruction, it appears that its use can only be justified when special circumstances apply.

One kind of special circumstance is when well-trained content teachers are not available. An excellent example of this is elementary science education. Joseph Novak (of the previous Postlethwaite group) developed elementary science lessons using ATI. In an extensive longitudinal investigation of the effects of ATI, Novak and Musunda (1991) reported a 12-year study of science concept learning. Twenty-eight of their best science concept ATI lessons were provided to 191 first- and second-grade children. Each lesson required 15 to 25 minutes to complete. As with the Postlethwaite materials, students were directed by the tape to interact with materials and pictures. The lesson were sequenced according to Ausubel's ideas about subsumption. Lessons were replaced after all students in the class had a chance to interact at least once. With few exceptions, all students were capable of proceeding through the lessons. Grade-I students completed lessons 1 to 16, and grade-2 students completed lessons 16 to 28. Lesson 16 was repeated. All lessons covered basic science concepts and principles. These children were compared by means of interviews to 48 uninstructed students in grades 2, 7, 10, and 12. Early on, the interviews included the use of tests with pictures or diagrams. However, these were later abandoned because they were judged to be confusing or misleading. Data collection evolved into Piagetian clinical interviews that were then translated into concept maps. Concept maps were then graded for valid and invalid notions. Instructed subjects showed significantly more valid concept understandings and fewer misconceptions. A significant interaction showed that instructed subjects, over the 12 years, had a greater tendency to increase their number of correct concepts and decrease the number of incorrect concepts. This exceptional study strongly supports the validity of ATI even under conditions where the instructors are not well trained. Valid concepts were learned from ATI and evidently "scaffolded" more learning throughout the children's 12 years of schooling.

In summary, audio-tutorial instruction is the most complete and most well-documented method of auditory presentation. It has a general record of success, and, although it is not noticeably superior to conventional approaches, it has many valuable ideas, even for other nonaudio forms of mediated instruction.