Early identification of reading difficulties using heterogeneous developmental trajectories.

Serious conceptual and procedural problems associated with current diagnostic methods call for alternative approaches to assessing and diagnosing students with reading problems. This study presents a new analytic model to improve the classification and prediction of children's reading development. Growth mixture modeling was used to identify the presence of 10 different heterogeneous developmental patterns. In all, 411 children in kindergarten through Grade 2 from 3 elementary schools in Texas were administered measures of phonological awareness, word recognition, and rapid naming skills 4 times a year. The mean ages were 5.8 years (SD = 0.35) for the kindergartners, 6.9 years (SD = 0.39) for Grade 1, and 8.0 years (SD = 0.43) for Grade 2; the percentage of boys was 50%. The results indicate that precursor reading skills such as phonological awareness and rapid naming are highly predictive of word reading (word recognition) and that developmental profiles formed in kindergarten are directly associated with development in Grades 1 and 2. Students identified as having reading-related difficulties in kindergarten exhibited slower development of word recognition skills in subsequent years of the study.