Intended for personnel in local school districts and state departments of education, this handbook presents suggested procedures and resources for the initial screening and diagnostic assessment of the English language skills of students whose dominant language is other than English. The handbook deals with the initial screening for placement and diagnostic assessment of English language skills at entry point. The diagnostic assessment procedures described deal with estimating the student's proficiency in the four English language skills (listening, speaking, reading, and writing). The following factors that must be taken into account in selecting tests that measure the English language proficiency of children whose dominant language is other than English are discussed: test appropriateness and linguistic, sociocultural, and psychometric criteria. Staff training is briefly discussed and a sample outline of an in-service program is provided. A listing of major sources of helpful measures includes the addresses of the 3 dissemination and assessment centers, 18 materials development centers, and 20 training resource centers. Appendices include a copy of the English Language P-Rating Sheet (Reading and Writing), a procedure for rating oral language proficiency, an excerpt from "Cloze Testing for Your Classroom," and a sample instructional plan (bilingual/ESOL). (NQA)