The value of H. Myklebust's Picture Story Language Test (PSLT) was examined in a study of differences in written expression between 85 learning disabled (LD) and 125 nonlearning disabled elementary grade children and characteristics of oral expression of the LD students. Using the PSLT, written and oral language samples were obtained from the students and analyzed for such variables as productivity and syntax. Though both LD and non LD Ss made the same types and percentages of errors, non LD children wrote with greater overall correctness and used twice as many words and sentences as LD students. The analysis of oral expression indicated LD Ss made errors in additions of words, omissions, substitutions, and word order in that frequency order. Results suggested that instruction of LD students should focus on adequate oral expression in the earlier grades and expansion of the quantity of words and sentences produced in the upper grades. An additional analysis of the PSLT led to the conclusion that the test is inappropriate for use above grade 2 and does not provide adequate diagnostic information. (An alternative diagnostic approach to written language is provided.) (BP)