Sentence combining as a technique for increasing adjective use in writing by students with autism.

A multiple-baseline across-subjects design was used to determine whether reinforcement alone or in combination with sentence-combining exercises would increase the number of descriptive adjectives used in daily writing samples by three adolescents with autism. The cumulative number of new adjectives (adjectives never before used by a student in the entire study) was also recorded. Experimental conditions were baseline, sentence combining, and maintenance. Writing sessions consisted of a 20-min worksheet period followed by a 20-min writing period. The addition of sentence-combining exercises increased the number of adjectives in the students' writing samples. Maintenance of this increase occurred in the absence of sentence-combining lessons and in the presence of reinforcement for use of adjectives. The addition of sentence-combining exercises also increased the cumulative number of new adjectives, although new adjectives did not occasion reinforcement, and we had not expected their use to increase in students with autism without specific instruction. Maintenance of new adjective use also was demonstrated. Finally, for all three students, minimal terminable unit (T-unit) length, a measure that facilitates comparison with normative data, increased from baseline to maintenance, and independent raters judged writing samples written during maintenance as better than those written during baseline.