This document discusses materials evaluation in language learning. It defines materials evaluation as the systematic appraisal of instructional materials to measure their impact on language learning quality. Materials evaluation examines the potential and practicality of materials, and helps teachers determine if materials should be adopted, maintained, or replaced based on their strengths, weaknesses, and how well they meet learner and teacher needs. The document also outlines the purposes of materials evaluation such as adopting new textbooks, identifying issues with current materials, comparing options, and informing teacher training. Both predictive evaluation of potential future materials and retrospective evaluation of past materials use are discussed.