This document examines the concepts of validity, reliability, and appropriateness from a language testing perspective as they apply to the following four assessment issues raised by the National Reporting System (NRS): (1) What type of language assessment seems to be required by the NRS: proficiency or achievement?; (2) Knowing that the NRS focuses on what the learner can do in the real world, and knowing the challenges to classroom teaching, what type of assessment would be most appropriate for the NRS?; (3) Knowing that all these variables need to be attended to, what does validity entail for appropriate NRS assessment?; and (4) What does reliability mean for performance measures meeting the rigorous requirements of the NRS? The document concludes that ensuring that language tests for adult English language learners are appropriate, valid, and reliable is challenging. Performance based assessments are inherently complex to develop and implement. Yet, because the focus of assessment--both in the NRS descriptors and in the Department of Education's definition of content standards--is on what learners can do with the language, performance assessments are worth developing and validating. (Adjunct ERIC Clearinghouse for ESL Literacy Education.) (Contains 16 references.) (SM)