THREATS TO THE VALIDITY OF SCIENCE PERFORMANCE ASSESSMENTS FOR ENGLISH-LANGUAGE LEARNERS

In recent years, at the same time that performance assessments in scie nce have become more popular, the number of English language learners (ELLs) (i.e., students whose native language is other than English) se rved by the U.S. educational system has also increased rapidly. While the research base is growing in each of these areas independently, lit tle attention has been paid to their intersection. This case study of the use of a science performance assessment with 96 ELLs in five high school science classes investigated the face, construct, and consequen tial validity of this intersection. Qualitative and quantitative data analyses showed that both teachers and students had an overall favorab le response to the assessment, although students' English comprehensio n and expression skills were determining factors for certain items. Wh ile most responses were reliably scored, ELL spelling and syntax on ce rtain responses were significant sources of error. The degree of speci ficity of teachers' guidance also significantly affected students' sco res. Recommendations from this study include increasing the clarity of an assessment's design, allowing ELLs more time to complete assessmen ts, and scoring by raters who are knowledgeable about typical patterns in written English for this student population. Furthermore, it is re commended that the use of performance assessments with ELLs be explora tory until such time as their validity and reliability with this popul ation can be more adequately established.