Investigated was whether retarded readers make more gain in reading achievement when taught by the regular classroom teacher using prescriptions written by the diagnostic teacher than they had under the traditional basal reader approach. Subjects were 17 fifth graders in the lowest reading group in a public school classroom. Subjects were tested to determine reading related strengths and weaknesses, skill deficiencies, and dominant learning channel. Materials were prescribed for each child to remediate his deficiencies. Children, taught for 1 year using the prescriptions, were pre and posttested with the vocabulary and comprehension subtests of the Iowa Test of Basic Skills. Reading progress was charted on a semi-logarithmic chart. It was found that prescriptive teaching was as effective as, but not superior to the basal reader approach in vocabulary building. In comprehension building, prescriptive teaching was superior. (Author/KW)