This volume examines the nature of second language listening proficiency and how it can be assessed. The book highlights the need for test developers to provide a clear explication of the ability constructs which underpin the tests they offer in the public domain. This is increasingly necessary if claims about the validity of test score interpretation and use are to be supported both logically and with empirical evidence. It operationalises a comprehensive test validation framework which adopts a socio-cognitive perspective. The framework embraces six core components, examining and then analysing Cambridge ESOL listening tasks from the following perspectives: Test Taker; Cognitive Validity; Context Validity; Scoring Validity; Criterion-related Validity; and Consequential Validity.