Competent middle school teachers must both extend students' abilities in the decoding and comprehending skills and stimulate their applications of these reading skills in content area texts. In considering this differentiation of instruction, teachers should be aware of an aptitude by treatment interaction (ATI)--no one technique will produce the same result for all students. Since in a typical middle school, student reading ability may span eight grade levels, with four possible variations of problems--organizational, decoding/vocabulary, interest/purpose, and experience background--differentiation of instruction must be process oriented. For each of these problem areas, various teaching techniques are practicable and effective. Throughout instruction, middle school teachers should remain cognizant of their roles in preparing independent learners for the content orientation of the secondary school. (A bibliography is included.) (JM)