ABSTRACT
There is a certain dichotomy in the evaluation literature between some basically different approaches to the evaluation of learning materials. Ideally, given the crucial importance of formative evaluation in improving the effectiveness of learning materials, schedules for their development should be planned to allow ample time for evaluation and, in particular, to allow for obtaining and using student feedback. In choosing the students who are to comprise a try-out group, the most important consideration is that they are selected from the intended target population. Iterative try-out and revision of draft learning materials is time-consuming and therefore expensive: When one balances the effectiveness of systematically developed instruction with its costs, it often may not be warranted. Equally, where the target population of students will be studying under compulsion, it will be appropriate for the try-out students also to study under compulsion – as in the case, for example, of Sulzen's investigation concerned with military training.
