Reading research for students with LD: A meta-analysis of intervention outcomes

The present article provides a meta-analysis of instructional research with samples of children and adolescents with learning disabilities in the doma ins of word recognition and reading comprehension. The results of the synth esis showed that a prototypical intervention study has an effect size (ES) of .59 for word recognition and .72 for reading comprehension. Four importa nt findings emerged from the synthesis: (a) Effect sizes for measures of co mprehension were higher when studies included derivatives of both cognitive and direct instruction, whereas effect sizes were higher for word recognit ion when studies included direct instruction; (b) effect sizes related to r eading comprehension were more susceptible to methodological variation than studies of word recognition; (c) the magnitude of ES for word recognition studies was significantly related to samples defined by cutoff scores (IQ > 85 and reading < 25th percentile), whereas the magnitude of ES for reading comprehension studies was sensitive to discrepancies between IQ and readin g when compared to competing definitional criteria; and (d) instructional c omponents related to word segmentation did not enter significantly into a w eighted least square hierarchical regression analysis for predicting ES est imates of word recognition beyond an instructional core model, whereas smal l-group interactive instruction and strategy cuing contributed significant variance beyond a core model to ES estimates of reading comprehension. Impl ications related to definition and instructional components that optimize t he magnitude of outcomes are discussed.