H–R–R Polychromatic Plates*

Abstract

A description is given of the H-R-R plates and evaluation of the test as a device (a) to separate those with defective color vision from those with normal color vision, (b) to classify the type of defect (qualitative diagnosis), and (c) to indicate the extent of the defect (quantitative diagnosis). For this evaluation 780 subjects were used, not selected on the basis of a statistical survey. The H-R-R plates are shown to be in complete agreement with the A.O. test (revised selection) in separating the subjects into two groups: 150 with defective and 630 with normal red-green vision. The test agrees remarkably well with the Nagel anomaloscope in classifying the subjects with defective red-green vision into deutan and protan types. It rates 23 percent of these subjects as having mild defect, 31 percent as having medium defect, and 46 percent as having strong defect. For the subjects with defective color vision, a detailed comparison is presented of the qualitative classifications into deutan and protan types yielded by the H-R-R plates with those made by the Nagel anomaloscope, the Tshihara test, and the dichotomous test. A further comparison is made for these subjects between the quantitative estimates of extent of defect by the H-R-R plates and performance on various aptitude tests which were designed to select those color-defective persons who can meet the color requirements of specific but different tasks. It is shown that the percentage who pass these tests significantly and consistently decreases as the severity of defect shown by the H-R-R plates increases. The practical importance of a simply administered, comprehensive test, such as is provided by the H-R-R plates, to vocational selection and guidance is discussed, and an example given of their application in the radio and television industry.