The effects of five secondary school individualized in-service training programs on classroom reading skills instruction are compared. The initial and final perceptions of the teachers, concerning their responsibilities for providing for pupils' individual differences in reading abilities, are measured by use of attitude inventories, self-rating scales, and/or summaries of their needs related to reading skills instruction. Verbal data are acquired during in-service training sessions, individual conferences, and classroom visits. Training content includes assessment procedures, teaching techniques, classroom management, grouping, and lesson planning. Four factors are considered strong influences on the in-service programs: training processes, training content, institutional influences, and consultants' influences. Three conclusions are reached: (1) teachers tend to give attention to existing reading programs in their schools as one means of providing for pupils' individual differences in reading abilities; (2) teachers tend to change their instructional procedures when receiving help with the problems of immediate concern to them; and (3) teachers tend to require instruction in classroom management and lesson planning before learning techniques for teaching reading skills. (AW)