This memo discusses the two most effective methods of performance appraisal, rating scale and 360-degree feedback, for quality control workers. It explains how these methods align with the eight key points of performance appraisal, including inclusion of both positivity and negativity, entries with date, observations, specificity, unbiased language, no generalization, determination of trend and pattern, and consistency. The memo concludes that these methods will help in effectively judging the performance of the employees without any biases, which will further help to improve their performance in quality control.