To date, little work has been done to ensure limited English proficient (LEP) students are accurately assessed on a large scale. The purpose of this guide is to help scorers in high volume situations to be able to effectively evaluate the open-ended responses of this population. Section one of this guide presents a brief overview of the State Collaborative on Assessment and Student Standards (SCASS) LEP Consortium Project and some background information about the nature and development of language proficiency. Section two, Effects of English Language Development on English Language Learner (ELL) Student Responses, provides guidance about linguistic and cultural issues associated with LEP students' learning English. Section three, Effects of English Language Development on Understanding and Interpreting Assessment Items, and section four, Issues Related to the Construction of Accurate Assessments for ELL Students, place the scoring of items in the larger context of test development and implementation. This guide is designed to be efficiently integrated into the regular training that scorers receive when they are preparing to score test items. This is designed to help large scale assessments become more reliable and responsible. Appendices containing the names of SCASS LEP Project committee members, references, and a glossary are appended. (Contains 13 references.) (KFT)