For more than a hundred years attempts have been made to fmd rational and objective methods to assess operators' task performance and to design reward systems that are based on these objective measures of performance. This is usually done by determining performance norms for a task and rewarding the operators' performance relative to these norms. Norms are established by observing and measuring the time required by one or more operators for the actual performance of a task, a technique called time studies. These measurements form the basis for the estimation of the standard time, i.e., the time required for the performance of a task by a "normal" operator. A normal operator is defined as a qualified, thoroughly experienced operator who is working under conditions as they customarily prevail at the work station, at a pace that is neither fast nor slow, but representative of average (Niebel, 1 972). This method is widely applied in industrial settings, whenever a job requires the periodic repetition of a sequence of activities (such as various assembly tasks). Operators are paid according to their performance compared to the norm and incentives are given for exceeding the norm.