A state-operated residential facility has for the past five years been using performance feedback as the primary method for improving direct care staff interactions with clients. The major problem with this approach is determining when staff performance is significantly above or below average. Statistical process control charts are being used to determine whether variations in staff performance are the result of common or special causes. Analysis of staff performance for one year suggests that variation in staff performance may be due to special causes, such as the characteristics of the clients served and the type of service that is provided to these clients. Services were adapted to the characteristics of these clients, which improved staff performance and reduced variation.