Measure Your Mind: The Mentimeter and How to Use It

by Marion Rex Trabue; Frank Parker Stockbridge

Fifteen geometrical figures, such as squares, circles, triangles, and the like, are presented on three pages of the examination booklet. To the left of each figure are two or more small figures which, when properly arranged, form the large figure on the right. The problem of the candidate is to draw a line or several lines in the large figure on the right to indicate how it might be divided to make up the small pieces shown on the left. The first figures are quite simple and may be very readily done by drawing one or two lines. The problems on the third page require from three to five lines to be drawn and are distinctly more difficult than the problems appearing on the previous pages.

It is very difficult to say exactly what functions of the mind are measured by this test. The greatest difficulty with the test is that a rather high minimum of intelligence is required in order to understand what is necessary or desired. The two examples appearing on the title page of the test booklet are not sufficient to demonstrate clearly to the dull person just what he is to do. It is probable that dull people will succeed very much better in this test if it is given as a test for foreigners, using the special blackboard. The examiner could, in that case, draw a line with chalk to show what is expected. The printed directions on the test blank have been made as simple as possible, but they are not wholly satisfactory for the lower ranges of intelligence.

The scoring of this test is somewhat more difficult than for the majority of the other Mentimeter tests. It is intended that one point of credit shall be given for each large figure properly divided. The difficulty comes in being sure that the candidate has intended to draw his lines at exactly the proper place. Inaccuracy may be the result of not knowing where the lines should be placed, or it may be the result of careless execution. If a line is misplaced through careless execution, when it is perfectly clear that the right idea was present in the candidate’s mind, full credit should be given for that element of the test. If it is not certain that the candidate understood where the line should be drawn, no credit should be given for that particular figure.

The stencils, which are supplied with each package of test booklets, should be placed to the left of the five geometrical figures and comparison should be made between the dotted lines of the stencil and the marks made by the candidate in the corresponding figure on the examination sheet. In the first square, for example, full credit should be given whether the line is drawn horizontally or vertically through the figure. The important thing is that two equal rectangles should be created by drawing a single line. Similarly, for each other figure, the important point to be considered is whether or not the lines drawn do form the geometrical figures shown on the left. A little practice will make it possible for the clerk who scores these tests to lay aside the key itself and to carry it in memory.

Various forms of this test have been used by psychologists for a number of years, although its most extensive use was in the Beta series of the United States Army. The same test in modified form was used by Prof. E. L. Thorndike in his tests of mental alertness in the air service. Many individuals were found who could do this test fairly well without being able to succeed with some of the others which were supposedly equally as good for general purposes. On the other hand, many individuals of good general ability were found who seemed lacking in the particular type of ability necessary properly to divide these geometrical figures. On the whole, however, the more intelligent men made higher scores than the less intelligent men. Such low relationship between this particular test and other tests of intelligence makes it particularly useful as one of a series to be used for measuring the intelligence of men entering certain mechanical trades where the recognition of the size and shape of objects is of prime importance. Draftsmen, architects, supply clerks, and candidates for similar positions would probably be rated more accurately by this test than would writers, musicians, and academic students.

In the public schools such a test might give some indication of the ability of children to succeed in mechanical or mathematical courses of study. In social gatherings, a great deal of amusement might be found by giving prizes to the individuals completing the entire fifteen figures correctly and in the shortest time. It would seem desirable, however, to omit the time limit when it is used for pure entertainment and to measure with a stop-watch the exact amount of time required for the individual. When all had finished the fifteen elements of the test, the papers could be checked up for accuracy and the prize could be given to the one who had finished correctly in the shortest length of time. This will add an element of interest for it is quite certain that some of those who finished first will have made errors, probably through careless execution, and that someone who finished later in the game will have drawn each line correctly.

Directions for Giving the Test.

a. As an individual test.

The individual to be tested should be seated at the left side of the examiner at a convenient table. The examiner should show the inside of the test blank to the candidate and should then point to the similar figures in the explanation on the title page of the booklet. He should then point to the large figure in the first example, possibly tracing its outline with his pencil. Then the attention of the candidate should be called to the parts appearing on the left-hand side. (Their outlines may be traced if it seems desirable.) Next, a movement should be made with the hand as though one were placing the parts upon the larger figure. This may be repeated two or three times, pointing first to the various parts in order and then to the large figure with a rather broad sweep of the hand. After such a study of the situation, the examiner should draw the proper line and exhibit a smile of pleasure at having successfully done the thing. He should point then to the parts of the large figure which are thus created and by jumping his pencil from one of the parts to the corresponding part on the left, he may fairly clearly demonstrate that he has constructed, by his line, elements which are similar to the elements appearing at the left.