In today''s new era of heightened accountability, English language learners (ELLs) are now included in the "teach-and-test" accountability system. Full inclusion of ELLs in accountability measures, however, does not necessarily mean more equity. Based on data-analysis of language-based assessment, this book shows how the socio-economic status (SES) factor affects groups differently. Regardless of English proficiency, SES matters less for low- achieving students. The impact of SES was greater, however, among high-achieving students. This suggests that the true ability of High SES ELLs is masked by their less developed academic-language proficiency in English, compared to their more English-proficient fluent counterparts. The results of this study show that tests developed for native speakers of English severely undermine educational equity for ELLs, and it raises the issue of the meaningfulness of such an educational policy that claims to provide accountability.