Reading comprehension can be considered a complex human performance involving two integrated repertoires: a verbal repertoire and an investigative (generative) repertoire. This paper describes an analysis of these repertoires in terms which can ultimately inform the design of programs to teach them, using the analysis and design of Headsprout[R] Reading Comprehension as an example. Although this paper has focused almost exclusively on analysis of content, it should be clear that analysis of learners' entering repertoires is also essential to programing instruction. Instruction must start from where the learner is (the learner's current repertoire) and bring that learner to where he or she needs to be (the goal of the program). (Contains 3 figures, 3 tables and 2 footnotes.)