Discourse complexity of college writers with and without disabilities: a multidimensional analysis.

The purpose of this study was to examine specific word- and sentence-level features most frequently used in the expository writing of four groups of college writers. Three groups were writers who demonstrated disabilities. Group 1 students (n = 87) demonstrated learning disabilities (LD); Group 2 (n = 50), attention-deficit/hyperactivity disorder (ADHD); and Group 3 (n = 58), combined LD and ADHD. Group 4 consisted of writers with no history of a documented disability (n = 92). Computer-based analysis and structural equation modeling were used to group specific linguistic features identified in the expository essays across all four groups. The frequency of linguistic features, not errors, was analyzed. Four communication dimensions (factors) were identified for the four groups of writers, but the factor loadings and correlations were significantly different across groups. Furthermore, the relationships of specific linguistic features were studied as to their impact on the verbosity, quality, and lexical complexity of students' expository essays. It is interesting to note that very high correlations were found between verbosity, quality, and lexical complexity, suggesting that these constructs are not as separate in their functioning as might be supposed. Implications for assessment and instruction are provided.