Although empirical data that support the reliability of assessment center regimes are sparse, an increasing number of police agencies have chosen to use it rather than other more traditional testing methods. One advantage of an assessment center is that its materials can be linked to the job for which candidates are being evaluated. Further, its procedures can be adapted to all types of positions and assignments. Also, when properly implemented, assessment centers are fair and objective in their evaluations. They are effective in testing how a person performs as well as what he/she knows. In addition, assessment center results can be used for multiple purposes and can provide feedback to candidates about their strengths and weaknesses. Still, assessment centers have limitations that may discourage their use in certain contexts. They cost much more than traditional testing programs and are difficult to administer effectively. Staff performance is crucial, and testing equipment must be properly maintained. Candidates have complained that the role-playing exercises fail to provide opportunities for them to display the full range of their abilities and that the limited amount of time spent with assessors is insufficient for a thorough evaluation. Another complaint is that a candidate's prior record of performance on the job is given little weight compared to the evaluation results from the center. The article advises that before an agency decides to use an assessment center to evaluate personnel for promotions, the investments involved in a well-run center should be researched and observed through site visits.