Cross-linguistic lexical task-Turkish (CLT-TR): Validity and reliability study

The purpose of the recent research is to conduct the validity and reliability study of the Cross-linguistic Lexical Tasks-Turkish (CLT-TR). CLT is developed within the scope of an international COST Project (IS0804) to measure the lexical knowledge of mono/bi/multilingual preschool children. There are 34 versions of CLT in different languages from all over the world. CLT consists of 128 items and 4 subtests namely Noun comprehension, Verb Comprehension, Noun Production and Verb Production. In the pilot study 25 typically developed (TD) children is included. Participants of the main study are TD 245 Turkish-speaking monolinguals and 30 developmental language disorder (DLD) aged between 2;00-4;11. In the scope of the item analysis, item difficulty and item discrimination indexes are calculated. Construct validity analysis shows a high internal consistency coefficient of the test items. There is a significant positive correlation between subtests and between subtest-total test scores. Participants performed higher on comprehension subtests and nouns comparing to the production and verbs. CLT scores vary significantly with age, and between TD and DLD groups. Within the scope of the reliability analyses, internal consistency, test-retest reliability and inter-rater reliability is examined. As a result of the analyzes, the reliability of CLT-TR has been revealed. Consequently, a new valid and reliable lexical assessment tool presented in the use of related professional fields. Keywords: Lexical knowledge, Language Development, Preschool, Developmental language disorder, Bilingualism.