A Selective Synthesis of Intervention Research for Students with Learning Disabilities

The present article provides a selective synthesis of instructional (intervention) research with samples of children and adolescents with learning disabilities. Intervention studies were analyzed across instructional domain (e.g., reading, social skills), sample characteristics (e.g., age, intelligence), intervention parameters (length of sessions, number of weeks), and sampling procedures (e.g., random assignment to conditions vs. intact groups). The synthesis indicated that (a) reading is the most researched domain, whereas mathematics and intellectual processing are the least researched, (b) intervention studies that produced the highest effect sizes were related to derivatives of cognitive and/or direct instruction; (c) no significant differences in effect sizes were found across response domains (e.g., reading, mathematics, spelling, language); (d) effect sizes for cognitive processes (e.g., attribution, metacognition, memory) were higher when coupled with academic domains than when “isolated” for intervention, and (e) effect sizes were significantly higher for intact or stratified groups when compared to randomly sampled groups. The limitations of current studies, as well as the current synthesis, are discussed.