The following is a situation in which information about a population is needed.

A large CPA firm has in effect a staff evaluation system by which all assistants are ranked on a scale ranging from 0 to 100. (100 is considered perfect.) Each supervisor ranks all assistants under his or her supervision with one number on the scale for each of several criteria, including accuracy of work, relations with the client, innovation, and neatness. There is also a numerical overall evaluation. Each assistant in the firm gets ranked approximately 30 times per year. Experience has shown that a few supervisors give abnormally higher or lower evaluations of a given assistant than other supervisors do. The firm would like a simple but useful evaluation of assistants that minimizes the effect of the abnormal evaluations but provides sufficient information. The firm does not want to identify which personnel give the abnormal evaluations.

Required:

a. Evaluate the advantages and disadvantages of each of the following three methods of summarizing the information for each employee for the situation described: mode, mean, and median.

b. Make a specific recommendation as to a method to be followed for summarizing the results for each employee.