Decoding, fluency, and reading comprehension in a morphologically complex transparent orthography: evidence from Turkish readers with learning disabilities

Abstract This study examines how decoding, fluency, and comprehension are associated in Turkish, a transparent yet morphologically complex orthography. Using the Simple View of Reading (SVR), the study explores how the decoding component operates in a writing system where phonological transparency coexists with dense suffixal structure. A total of 172 s- and fourth-grade students completed standardized assessments of decoding accuracy, error profiles, root–suffix error distribution, reading fluency, and comprehension. Cross-sectional analyses indicated higher error rates among students with learning disabilities (LD), with more errors in suffixes, suggesting increased processing demands in word-final segments. Reading fluency strongly differentiated groups at both grade levels. Developmental analyses showed that decoding and fluency were associated with comprehension when sufficient variability was present, whereas restricted variance among older LD readers attenuated these associations. Response-time patterns suggested differences in processing depth rather than efficiency. Overall, the findings provide cross-linguistic evidence illustrating how decoding efficiency may be shaped by orthography-specific structural complexity within the SVR framework, without challenging its core assumptions.