The chief value of this examination of Poincaré does not lie in the particular results which it yielded, but in its initiation of such attempts to study in a more or less intimate and intensive way the psychological processes and type of individuals of marked achievement in special lines of work. For the purposes of vocational psychology it would be valuable to know the ways in which such admittedly superior individuals as those now being studied by Dr. Toulouse, differing as they do in their types of achievement, would react to the simple and complex tests now employed by those interested in the measurement of intelligence and special aptitudes. It is true that these psychographic methods do not yet yield results which are sufficient to inform us why the particular individuals examined were so much more successful in their work than were others who seem to have been equally favored and equally diligent. Nor have they yet revealed in any adequate way the nature or degree of the qualifications requisite for success in the vocations from which the representative men have been selected. Nevertheless the individual psychograph constitutes a suggestive method of research for the vocational psychology of the future. It represents the intensive development of the older type of "biography," based on direct observational data rather than on hearsay, conjecture and anecdote.
It is on some variation of this method that we must largely rely in our efforts to learn to what degree vocational success depends on the presence of demonstrable personal characteristics, rather than on the accidents of time, place and circumstance. It was inevitable that the first attempts to give psychographic accounts of the personality of individuals of genius should be more or less fragmentary, incomplete and experimental. This has been due partly to the rapidity with which our knowledge of mental tests has developed, and partly to the very complex and subtle types of achievement toward which these early psychographic methods have been directed. Various investigations are now under way in which these same methods are being used in the intensive examination of individuals who have engaged in simpler and more common forms of activity, with varying degrees of success. In some of these researches, for example, men who have made their life work the marketing of a specific type of commodity through direct and personal salesmanship are being submitted to intensive psychological examinations. The problem is to discover whether there is a more or less specific and recognizable type of personality which characterizes the successful salesman and differentiates him from the mediocre salesman and the utter failure. Directed toward these more familiar and more easily accessible occupations, the individual psychograph constitutes one of the most interesting forms of vocational psychology. Closely related to it, though sufficiently distinct in aim and method to merit separate presentation, is the method of the vocational psychograph, in which the work, rather than the worker, is made the object of analysis.