Ability to master a language is usually very closely related to general intellectual ability along academic or abstract lines. The relationship between the age at which a child begins to talk and the length of time required later by the same child to learn to use a foreign language would probably be found fairly close.
The Digit-Symbol test has been used rather extensively and for many years as a form of measuring the ability of an individual to learn a new method of expressing himself. Many experimenters have used a Letter-Symbol test rather than the Digit-Symbol, but there seems to be little difference in the character of the results obtained.
The Mentimeter form of the test follows quite closely the corresponding test in the Beta series used in the Army. At the top of the page there appears a key showing just what symbol should be used to indicate each number or digit. The test itself consists of 100 digits with empty squares appearing below them in which one is to write, beneath each digit, its corresponding symbol as shown by the key on pages [166] and 167. An intelligent person usually begins with the first digit and supplies the proper symbol for it at each place it occurs in the test; then begins with the second digit and goes through the entire test writing the symbol for it, and so on. Those of average intelligence more frequently try to supply the proper symbol for each different digit in order as they appear in the test without going through the entire test with each symbol separately. The method of the candidate in doing the work should not, however, be allowed to influence the rating obtained on the test, except as one method may produce a higher score than another.
Investigations which have been made seem to show that although the symbols used are quite distinctly more difficult to write than the digits themselves would be, it is nevertheless a better test to measure the number of symbols the candidate can write under the digits than to measure the number of digits one could write correctly under their corresponding symbols. The relationship between ability in this test and general ability to handle ideas and abstract notions is rather remarkably close. It is probable, however, that if the test were lengthened so as to require five or ten minutes rather than two and one half minutes the correspondence with intellectual ability would be increased.
This test will be very useful to employers seeking high-grade clerical service and probably in selecting administrative or supervisory officers. In the public schools it will be useful in some instances in classifying pupils for instruction. As a diversion in the home or social group it will have slight value.
Directions for Giving the Test.
This test has ordinarily been given as a test of several individuals at the same time. It is probable that it will not be as useful when given to one individual at a time as when used as a group test. The instructions are given here, however, as with the remainder of the tests for non-English-speaking persons, with the needs of examining foreigners individually uppermost in mind. By reproducing on the blackboard or on a wall chart the introductory examples one may adapt with almost no change the method of administration here described so that it will work equally well with a group. It is advisable to prepare such introductory charts and to give the tests as group tests rather than as individual tests, not only with the Digit-Symbol Substitution test but also with the other Mentimeters numbered from 2 to 10.
Key: This shows the mark for each number
Make under each number the mark which should be there