A study followed three textbook adoption committees as they evaluated basal reading programs. The committees used "A Guide to Selecting Basal Reading Programs" (developed at the Center for the Study of Reading) to help them evaluate the quality of instruction in existing programs. Case studies of the three committees sought to address the following issues: (1) whether the Guide was helpful; (b) whether it helped committee members focus on the instructional content; (c) whether it influenced teachers in becoming more critical consumers of basal materials; and (d) whether there were factors which contributed to the use of the Guide. All committee members were asked to read the booklets in the Guide and were observed as they used the Guide to evaluate programs. Members were asked to fill out questionnaires to find out whether the Guide was of help and to determine whether it helped them focus on the instructional quality of the basal reading programs. Structured interviews followed classroom observations to determine if teachers had changed their thinking or teaching behaviors. Results showed that 80% of the committee members felt that the Guide was helpful. Research indicated that use of the Guide improved the selection process by giving members information about current reading research, by providing specific criteria for evaluating basals, and by giving committee members a common framework in which to understand what they were evaluating. The extent to which the booklets helped teachers become more critical consumers depended upon each individual teacher's level of prior knowledge and training. Four factors appear to have contributed to the Guide's successful use: time, enthusiasm of committee members, in-service training, and leadership. (Three tables of data are included, and 27 references are attached.) (MG)