There are many types of human resources, training, and labor relations managers and specialists. In a small organization, a human resources generalist may handle all aspects of human resources work, and thus require an extensive range of knowledge. The responsibilities of human resources generalists can vary widely, depending on their employer's needs. In a large corporation, the director of human resources may supervise several departments, each headed by an experienced manager who most likely specializes in one human resources activity, such as employment and placement, compensation and benefits, training and development, or labor relations. The director may report to a top human resources executive. Establishing and maintaining a firm's pay structure is the principal job of compensation managers. Assisted by compensation analysts or specialists, compensation managers devise ways to ensure fair and equitable pay rates. They may participate in or purchase salary surveys to see how their firm's pay compares with others, and they ensure that the firm's pay scale complies with changing laws and regulations. In addition, compensation managers often oversee the compensation side of their company's performance management system. They may design reward systems such as pay-for-performance plans, which might include setting merit pay guidelines and bonus or incentive pay criteria. Compensation managers also might administer executive compensation programs or determine commission rates and other incentives for corporate sales staffs.