INTRODUCTION The problem of the measurement of the degree of attention has for some time been recognized by writers of the highest authority as one of the central problems of experimental psychology. There is, consequently, no need to dwell upon its importance. What is believed to be a satisfactory solution of this problem is offered in the following pages. While the writer is of the opinion that an accurate and practicable method for the measurement of the degree of attention has not hitherto been described, it is only fair to acknowledge that many methods have been proposed. The reader who desires a critical historical study of methods of measurement of attention may be referred to Geissler.1 In summary, Geissler writes: "We have thus completed our review of the experimental work upon the problem of measuring the attention and may conclude, on the one hand, that, although much effort has been spent upon it, we are still far from a satisfactory solution. On the other hand, we are now better able to judge which paths would seem most promising for future experiments and which should be abandoned." As regards Geissler's own contribution, the main conclusion at which he arrives is the following: "A very close parallelism was found to exist between introspectively distinguishable variations of attention and corresponding differences in the precision of work performed at these levels, under the condition that the estimation of degrees of attention was made in terms of clearness and that the work itself was not influenced by anything else but change in attention." That a parallelism exists between degree of attention and various kinds of work has long been taken for granted. Indeed, it is hard to imagine any psychophysical work in which attention is a factor, the efficiency of which would 1 Amer. Journ. of Psychol., 1909, 473-529. |