for them a more appropriate time. Dialog memorization, newspaper reading and study of grammar may proceed in any order, or simultaneously. A second advantage is that, for example, a set of readings or dialogs appropriate for well-diggers may be replaced by a set appropriate for TB control workers without tearing the whole course apart. (For examples, see Chapter 4 and Appendix G.)
In any case, modular construction may lead to greater responsiveness (Assumption III) and hence to greater usability (Assumption I). An incidental advantage for the overworked writer who is producing materials on marginal time is that one fascicle can be completed and put into use in a small fraction of the time it takes to write a complete course.
It may be objected that drawing on an array of modules and combining them into a successful course places heavy demands on the teacher's ingenuity and judgment. That is certainly true. But exactly the same is true if one is to teach successfully from a printed course, bound between covers, conceived and written by strangers who were removed by many months and many hundreds of miles from one's present students.
Modularity is a principle or an approach, and not a method. Specifically, as Allen Weinstein has pointed out (private communication)
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