The relationship between the word and the sentence structure of the texts in Turkish coursebooks and their readability levels

In this research, it has been tried to identify the relationship between the texts in Turkish course books and the readability level of the word and the sentence structure. The research has been practiced in the design of document review. The population of the research has been formed by The Turkish coursebooks that published by the Ministry of Education and taught in 5, 6, 7 and 8th grade in 2012-2013 academic year. A text ?excluding poems and drama texts- has been chosen from each theme in Turkish coursebooks. The study has been carrried out on 25 texts in total. In order to determine the readability level of the texts in Turkish coursebooks, the readability formula that has been adapted to Turkish with reference to Flesch formula by Ateşman (1997) has been used. In terms of identifying the word and sentence structure of the texts, it has been benefited from the curriculum of the Turkish lesson in 6, 7 and 8th grade and explanations in teacher guidebooks. The students knowledge and comprehension skills about the word and sentence structure have been considered. In total 300 words and 30 sentences from the beginning, the middle and the last part of the text have been chosen on the purpose of analysing the word and sentence structure. In the analysis of the data acquired from the assessment instrument ANOVA test has been applied. In the presence of the differences between groups, among the multiple comparison tests, the results of LSD test have been examined. The significance level has been accepted as .05 in the research. In the research result, it has been observed that the coordinate and compound sentences have been used less in 5th grade level texts than 6, 7, 8th grade texts. The number of the words that take a derivational affix has been used more in the texts that considered as medium or hard level than the easy level texts. The number of the words that take a inflexional suffix has been used more in the easy level texts than than the medium or hard level texts. Simple words are used more in easy level texts than medium and hard level texts. Derived words are used less in easy level texts than medium and hard level texts. The number of the simple sentences has been seen more in easy level texts than the medium and hard level texts. Key words: Readability, Word Structure, Sentence Structure, Turkish Coursebook