This report compares the relative improvement in reading shown by students taught by teachers trained in the diagnostic/prescriptive approach with those taught by teachers using a conventional method. Subjects were 239 control and 261 experimental students, matched in basic demographic characteristics and in IQ scores, from grades four through six. Twelve control and 12 experimental teachers each taught reading to approximately 25 students. All teachers received inservice training one hour a week, with the experimental teachers receiving an additional three hours of inservice training each week in the diagnostic/prescriptive approach. Pretests and posttests were administered to the students, while the Minnesota Teacher Attitude Test measured teachers' attitudes toward their students. Findings show that inservice teacher training produces higher levels of student spelling ability, that the same may be true of student reading ability, and that teachers' attitudes directly influence student progress. Tables of findings are included. (JM)