This report provides an analysis of data from the 1978-79 school year that was collected in an evaluation of reading materials used for instructional purposes in grades one through six of the District of Columbia public schools. Following a discussion of the scope and purpose of the evaluation project, the report provides findings that address the following questions: (1) What are the most frequently used reading materials in grades one through six? (2) What reading score gains are associated with what reading materials? (3) Do some reading materials appear to be more effective than others? and (4) Is there a benefit to students if the same reading material series are used at each successive grade level within a school? Appendixes contain a list of the schools participating in the evaluation and replicas of the classroom/student background form and the reading program form used in the evaluation. (FL)