| Several states have seen recent changes in their policy regarding the testing of English Learners (ELs), who by definition are not yet proficient in the language of the test. As many states are urged to include ELs in large-scale testing, many question the validity of achievement test scores because the degree to which the test score is a function of language proficiency is not clearly understood. This study investigated DIF (differential item functioning) on the NAEP (National Assessment of Educational Progress) between a group of second language English learners and native English speakers. A linguistic analysis of test items was used as an external criteria to understand differences in test item functioning. No DIF was found; however, as the item format became more open, linguistic complexity of test items increased, affecting the test scores for second language English learners, but not the native English speakers. To further investigate how language factors affect test scores for ELs, there is a need for access to larger databases of ELs with multiple, well-defined measures of English proficiency. |
