Chapter 5 described how frame-of-reference (FOR) training can be successful in improving the accuracy of supervisors as they assess the performance of their subordinates in the context of a performance management system. This same type of training method can be used for training assessors. One study including 229 I/O psychology students and 161 managers demonstrated the effectiveness of FOR training for training assessors in ACs. Results showed that not only did FOR training outperform a minimum training condition, but it also outperformed a data-driven training program that covered the processes of observing, recording, classifying, and evaluating participant behavior. Specifically, interrater reliability and rating accuracy were better for the FOR training condition than for the data-driven training condition. There is additional evidence that implementing FOR training improves both the criterion- and the construct-related validity of ACs. In the end. Participating in FOR training produces assessors that are more experienced with the task and rating system. Such experience is known to be an important predictor of assessor accuracy.