This guide has the broad purpose of improving large-scale academic assessments for limited-English-proficient (LEP) students. It was written because large-scale assessments are studded with problems that affect not only how equitable the achievement of LEP students can be measured, but also how effectively LEP students' mastery of content is assessed. LEP students may understand more than they are allowed to demonstrate under the confines of large scale tests designed for mainstream use with students sharing common cultural experiences. This guide is designed to provide both practical, research-based information for individuals and groups developing and administering tests of academic achievement for LEP students. It is also intended to provide lucid, easily accessible knowledge for policymakers that clarify the complex issues facing LEP students. The guide is organized into 10 chapters with two appendices. Chapters cover the following topics: issues of alignment, inclusion, and participation; alignment of performance standards to content standards; test specifications and the accessibility framework for LEP students; accessibility on writing terms; writing accessible rubrics; promising administrative and response accommodations; expanded bias reviews; scoring constructed response items; demonstrating the technical merit of assessments; and accessibility considerations when reporting and using test results. The appendices offer a technical discussion of issues related to accessibility and the highlights of key research on assessment of LEP students. (Contains 60 references.) (KFT)