Knowledge of suffixed words in reading and oral language contexts: A comparison of reading-disabled and normal readers

The present study was undertaken to measure and compare reading disabled and normal readers' knowledge of derivational morphology, particularly their knowledge of suffixed words. Knowledge of derivational morphology is considered important for vocabulary acquisition; however, only minimal research has been done in this area. Two experimental tests were designed for the study. The Semantics Test measured the subjects' ability to extract lexical-semantic information from suffixed words, and the Syntactics Test measured the subjects' knowledge of the part-of-speech contribution of derivational suffixes. Each experimental test had a reading and an oral language subtest. Three groups with 20 subjects in each group were selected for this study, a group of sixth-grade reading disabled students (6RD), a group of fourth-grade normal readers (4N), and a group of sixth-grade normal readers (6N).;The results showed that the 6RD group scored similarly to the 4N group on the reading subtests. However, on the oral language subtests, the 6RD group scored more like their age-matched peers (6N). On the Oral Language subtest of the Semantics Test the scores for the 6RD group were not significantly different from those of their age-matched peers. Thus, the reading disabled students were better able to demonstrate their knowledge of suffixed words on oral language measures than on reading measures.;The study also considered whether there was a relationship between knowledge of derivational morphology and reading comprehension ability. Scores for the 4N and 6N group were used in standard multiple regression analyses to determine whether the experimental measures in the present study accounted for significant amounts of variance in reading comprehension. For the 4N group, independent variables from the Semantics and the Syntactics Tests accounted for significant amounts of variance in reading comprehension. For the 6N group, independent variables from the Semantics Test accounted for significant amounts of variance in reading comprehension. The number of significant equations and high squared multiple Rs for the regression equations indicated a strong relationship between knowledge of suffixed words and reading comprehension ability and signaled that this is an important area for further investigation and research.