This book explores the notion of validity evaluation as a means for helping educators to ensure the utility and worth of their assessment practices. With a particular focus on foreign language testing the author challenges assessment traditions and argues for a fundamental reconceptualization of assessments and their validation in language teaching and other educational settings. Following a critical review of test validity standards and methods within educational measurement the author then proposes a comprehensive alternative approach to validation based upon program evaluation methodology. A report of a multiyear case study completes the volume providing indepth analyses of how validity evaluation methods were applied by foreign language educators in meeting the assessment needs of a German program at a US university.