SummaryThe logicand the techniques of personnel research have been developed and applied primarily in the field of test construction. They are, however, as applicable to the evaluation of a personnel program as to the appraisal of an individual. In such application the interdependence of the various parts of the total personnel program are shown as they actually function, rather than as they are “dreamed up” on an organization chart. Moreover, the importance of such intangibles as quality of staffing and degree of coordination can be compared to determine how much each contributes to the total effectiveness of the over‐all personnel program.Coordination in personnel work, as in any other activity, is generally recognized as being highly desirable. Alert administrators attempt by conferences, by issuances and by personal contacts to achieve coordination within and betweenThis article establishes on a factual basis, rather than by mere assertion, the value of coordination among the parts of a personnel program in achieving an effective total product. Moreover, it points out in a set of particular situations how coordination among the various branches of a personnel department can best be undertaken.Some of the activities of a single Branch of a personnel office have an impact in every corner of the department; others among a Branch's activities are literally nobody's business but its own. This study differentiates among these, and gives direction to coordination by specifying which interbranch contacts are shown to be most important to over‐all effectiveness; it specifies also how the activities carried out in one Branch, e.g., Placement, have implications for the success of another Branch such as Salary and Wage Administration. It provides factual answers to the questions: “To what extent and in what respects must the job analyst, the placement interviewer, the training instructor, the employee counselor and other personnel workers each know what the other is doing? How is the work of one affected by how good a job the other does?” From the specific answers to these questions come answers to the broader ones: “How can each do his job most effectively?” and “HOW can duplication of effort, neglected needs, or contradictory policies and practices be redu