The Cross-Linguistic Lexical Task in bilingual children from Luxembourg. Psychometric properties and clinical implications

The purpose of the present investigation was to examine the psychometric properties of the Luxembourgish version of the CLT in a multilingual sample of preschoolers and to identify implications of the instrument for clinical practice.
Participants were 40 monolingual and 40 bilingual children with a mean age of 5 years and 10 months. Children were recruited from Year 1 and Year 2 of Luxembourgish kindergartens. Monolingual children spoke only Luxembourgish at home and in school. Bilinguals had lived in Luxembourg for at least 2 years and came from families where one or both parents indicated speaking another language than Luxembourgish at home. Groups did not differ significantly in age, gender, or socioeconomic status. Children completed all 4 subtasks of the CLT-Lu (noun & verb comprehension and production tasks respectively), and a nonword repetition and digit recall task assessing phonological processing and verbal short-term memory.
All CLT subtasks reached sufficient internal consistencies with Cronbachs alpha’s ranging between .77 and .91. If the sample was split into monolingual and bilingual groups, reliability remained satisfactory for the production tasks (alpha’s between .70 - .90). Word comprehension could, however, only be reliably assessed in bilinguals (alpha’s of .73 and .79); monolinguals scored at ceiling. The CLT measures correlated significantly with digit recall and nonword repetition (r’s between .42 - .50). On average bilinguals scored three standard deviations below the performance of the monolinguals on all CLT subtasks and difference were larger for nouns than for verbs.
The study indicates that the CLT is a promising tool to reliably assess word comprehension in monolingual and word comprehension and production in bilingual preschool children in Luxembourg. However, it is crucial to test bilingual children in all of their languages and to establish specific bilingual norms in order to get a better indication of their verbal abilities.