The score in this test is the number of symbols correctly supplied. Marking the errors is very much simplified by the use of the stencils furnished with each package of test booklets. The number of symbols correctly written should be recorded at the end of each line in the test and the total for all lines should be entered in the lower right-hand corner of the title page of the booklet. Scores from 0 to 20 indicate Inferior Ability Scores from 21 to 35 indicate Low Average Ability Scores from 36 to 65 indicate Average Ability Scores from 66 to 75 indicate High Average Ability Scores from 76 to 100 indicate Superior Ability MENTIMETER NO. 9 COMPLETION OF NUMBER RELATION SERIES _Character of the Test._ This test may be given to any individuals or groups of persons who can read and understand the arabic numerals. The directions furnished herewith are for the measurement of a group rather than of an individual, although with very slight modifications in instructions the test leaflet may be employed in an individual psychological examination. The title page of the leaflet contains fairly complete directions and three samples of the number series to be completed. Persons who read English readily will have a distinct advantage over those who must depend upon oral instructions, but experience has shown that, even with individuals who do not understand the English language, it is possible to demonstrate on a blackboard, using the sample exercises, with sufficient clearness to enable foreign language-speaking candidates to grasp the idea of the work to be done. No comparisons should be made, however, between results obtained by oral demonstration and results obtained through the use of the instructions printed below, without making allowances for the differences in method of administration. The Number Relation Series test is so difficult to understand that it is hardly worth while to employ this test with children below ten years of age or with adults whose mental capacity is not equal to or better than that of the ten-year-old school child. The method of marking the test is quite simple when one is supplied with the stencil which is furnished with each package of test blanks. The present form of the test is somewhat different from those used elsewhere and it is difficult to say just what phases of intellectual or mathematical ability are measured by it. The Army intelligence tests included a number relation series test, so arranged that the last two numbers in each series must always be supplied by the person tested. Dr. Agnes Rogers, in her study of the prognostication of mathematical ability, employed a test which is very closely related to the one given here. Her results seem to show that this form of test is a splendid measure of mathematical capacity in high school pupils.