Measurement of early literacy skills among monolingual English-speaking and Spanish-speaking language-minority children: A differential item functioning analysis

A critical issue in psychological and educational testing is whether assessments provide reliable and valid estimates of ability for different populations of individuals. This issue may be particularly relevant for populations who are not native speakers of the language in which the assessment is written. Therefore, the purpose of this study was to evaluate the utility of a norm-referenced assessment of English early literacy skills for Spanish-speaking language-minority (LM) children. Participants for this study (1221 preschool children, 751 of whom were identified as Spanish-speaking LM children) completed the Phonological Awareness, Print Knowledge, and Definitional Vocabulary subtests of the Test of Preschool Early Literacy (TOPEL). Item response theory analysis was conducted to examine student performance on each subtest, and performance of monolingual English-speaking and Spanish-speaking LM children was compared using differential item functioning (DIF) analysis. Results indicated that there was minimal DIF for the Phonological Awareness and Print Knowledge subtests. Substantially more DIF was evident on the Definitional Vocabulary subtest, although presence of DIF was not consistently in favor of monolingual English-speaking or Spanish-speaking LM children. Moreover, effect size estimates of DIF indicated that, across most test items, the magnitude of DIF was small to moderate. Taken together, these findings indicate that the TOPEL can be used to obtain valid and reliable estimates of Spanish-speaking LM preschoolers' English early literacy skills. (C) 2018 Elsevier Inc. All rights reserved.