THE MEASURE OF COMPARATIVE PRODUCTIVENESS 3OI the employment manager or the committee which is sup posed to assist in the decision is still largely dependent upon a set of extremely variable personal opinions. It must rely either upon the word of the employee in ques tion, or upon general impressions of its own, or upon the word of the foreman. In the midst of this conglomeration of personal opinions, that of the foreman is bound to have the greatest weight, because it has the authority of one who is most closely in touch with the employee and who, even if he does not know the employee well, is at least supposed to know him better than anybody else. Most companies endeavor to cast light upon this prob lem by computing their percentage of labor turnover, and by trying to analyze and interpret this percentage. This is a valuable step in determining the degree of agree ment between selection and retention. However, up to the present time labor-turnover figures have remained very largely an unfathomable mystery. Although it has been possible to give roughly some of the principal reasons for labor turnover, it is generally acknowledged that an extremely large proportion of reasons for leaving hinge upon personal factors which, in the present scheme of things, can never be adequately determined. As long as the process of retention is based principally upon a large variety of constantly changing personal equations instead of upon some standard and impersonal basis, turnover fig ures will retain their sphinx-like inscrutability. Many com panies have an attendance record and a few are now keep ing a record of the work done by each employee; but on the whole, these records are still very haphazard and their full value is not yet grasped. Nevertheless, such records are the greatest single advance in the right direction. In order to minimize the errors due to the personal equation,