The "Washington English Language Proficiency Assessment" (WELPA) is a No Child Left Behind (NCLB)-compliant instrument that is used in Grades K-12 as a formal and standardized method of measuring language proficiency. The test results provide important information for classifying English Language Learners (ELLs) and subsequently for monitoring their progress in acquiring English. The assessment measures the federally required competencies necessary for successful academic and social language usage in mainstream classrooms: Speaking, Listening, Reading, Writing, Comprehension, and Overall. Additionally, composite scores are provided for Oral and Productive language as well as for Literacy. The WELPA was built from McGraw-Hill Education CTB's LAS Links® English Language Proficiency Assessment and aligned to the Washington State English Language Development (ELD) Standards. The new Proficiency Level Descriptors (PLD) and the new English Language Proficiency (ELP) Standards can be found at http://www.k12.wa.us/MigrantBilingual/ELD.aspx. This Interpretation Guide is designed to: (1) outline the content of the WELPA; (2) provide proficiency level cut points and Performance Level Descriptors; and (2) help interpret test data.