Reading Failure in a Completely Transparent Orthography Representing a Morphologically Highly Complex Agglutinative Language: the Case of Turkish

This study investigates differences in the word processing skills of students with and without reading difficulties who read Turkish, an entirely transparent orthography. Thirty-five students diagnosed as poor readers and 51 typically developing controls were tested across two experiments, one that assessed their ability to process identicalness of isolated real words as opposed to pseudowords and another that assessed their ability to judge semantic relatedness of two real words. Participants were from two education levels; half of them were 3rd-4th graders and half were 6th–7th graders. An integrative view of the findings points to an apparent failure of Turkish poor readers to develop a lexicalized reading route that mediates word recognition by means of permanent orthographic knowledge. Moreover, their ability to effectively process word letter sequences along a non-lexical grapheme-to-phoneme conversion-based reading route was found to be seriously restricted. Findings are discussed with direct reference to orthographic transparency, dual-route reading theory and the orthographic self-teaching concept.