Assessment centers (ACs) are used to evaluate individuals on key skills, abilities, and behaviors needed for a job. An AC involves multiple assessment exercises observed by trained evaluators. Exercises may include in-basket tests, leaderless group discussions, and case analyses. Evaluators are trained to observe behaviors, categorize them by dimension, and rate individuals. ACs provide structured evaluations of behaviors across situations. They have been shown to be effective and valid for selection and development purposes when properly designed and implemented.