Presented at the 15th Annual World Congress on Learning Disabilities, Burlington, MA, 26–28 October 2006

Students at-risk for learning difficulties and academic failure often include those whose first language is different from the language taught at school and students with limited reading experiences due to reading difficulties or disadvantaged environment (Snow et al., 1998). Current theory emphasizes vocabulary instruction and use of decontextualized language in schools because of the strong relation demonstrated between vocabulary skills and reading achievement. The present study explores this relation in regards to growth of cognitive academic language proficiency (CALP according to Cummins, 1979) in both first and second language learners. Specific goals are to investigate language skill differences and their potential contribution to reading achievement among three different groups of Greek students: (a) disabled readers, (b) children of immigrants who speak Greek as their second language and (c) typical Greek readers. The sample included approximately 120 children in grades 2–4 from 17 Greek schools. Group differences in academic and regular vocabulary knowledge, word decoding, word spelling, and reading comprehension were examined first. The contribution of scores in academic and regular vocabulary knowledge to systematic variability in word decoding and reading comprehension for each group was then examined in a series of hierarchical multiple regression analyses. The results are discussed with respect to educational implications and in connection with factors potentially affecting vocabulary skills such as socioeconomic status and cross-linguistic differences.