Manual of mental and physical tests : a book of directions compiled with special reference to the experimental study of school children in the laboratory or classroom / by Guy Montrose Whipple.
- Guy Montrose Whipple
- Date:
- 1910
Licence: In copyright
Credit: Manual of mental and physical tests : a book of directions compiled with special reference to the experimental study of school children in the laboratory or classroom / by Guy Montrose Whipple. Source: Wellcome Collection.
432/566 page 406
![Method.—Arrange the table at such a height that S’s forearm will be parallel with the floor when lifting a weight. Spread the black cloth over the table: this cloth should be large enough to cover at least the portion of the table occupied by the weights, and thick enough to deaden the sounds incident to their replace- ment. Arrange the twenty comparison blocks on the cloth, in the order of their weight from left to right, and in such a manner that any one of them may be reached by S without materially changing the angle of his arm. Place before S the larger standard block, and say: “Here is a block. I want you to find a block in this series of 20 blocks that seems to you just as heavy as this one. Lift it by picking it up edgewise with your thumb and finger, like this. [Illustrate.] Then try the first of these weights [at the left]. If that doesn’t suit, try the next, then the third, and so on, till you find a block that seems equal to this one. Each time you must lift this block first, then the one you are trying in the series. Keep your eyes constantly directed at the weight you are lifting.” When S has selected an equivalent weight, the same procedure is followed with the second, or smaller, standard block. Our estimate of the absolute or relative weight of a body is conditioned by an unsuspectedly large number of factors,the analysis of which has been the occasion of a number of extended and carefully-executed researches.1 While space forbids a discussion of these factors here, it should be impressed upon E that the conditions under which S lifts the blocks should be kept as uniform as possible. Particularly, since the apparent weight of a body de- pends in part upon the velocity and height to which it is lifted, it is im- portant that S should pick up each block in the same manner, lift it at the same tempo and to the same height. Again, since the memory image for weight changes rapidly, S’s judgment, in so far as it is based upon the image of the first weight, would be appreciably altered if the second weight were lifted at varying intervals after the first: the interval should, accordingly, be made as constant as possible, and fairly short, say not over 3 sec., and the arrangement of the weights must be such as to permit this procedure. Finally, in this test, since the suggestion hinges upon the visual perception of the block, E must be sure that S looks directly at each block as he lifts it. 1 See particularly, Martin and Muller, and Muller and Schumann.](https://iiif.wellcomecollection.org/image/b28083179_0432.jp2/full/800%2C/0/default.jpg)
