pairs of words of which the two members of the pair always logically belong together. Later, one word of each pair will be read to them and they have to write down the word which belonged with it in the pair." (For example, "thunder" and "lightning" are words that "logically belong together," while "horse" and "bricks" are unrelated terms.—Editor's note.)

"This is not a simple experiment on memory. The tests have shown that if, instead of logically connected words, simply disconnected chance words are offered and reproduced, no one can keep such a long series of pairs in mind, while with the words which have related meaning, the most intelligent pupils can master the whole series. The

very favorable results which this method had yielded in the classroom made me decide to try it in this case, too. I chose for an experiment twenty-four pairs of words from the sphere of experience of the girls to be tested." (For instance, "door, house"; "pillow, bed"; "letter, word"; "leaf, tree"; "button, dress"; "nose, face"; "cover, kettle"; "page, book"; "engine, train"; "glass, window"; "enemy, friend"; "telephone, bell"; "thunder, lightning"; "ice, cold"; "ink, pen"; "husband, wife"; "fire, burn"; "sorry, sad"; "well, strong"; "mother, child"; "run, fast"; "black, white"; "war, peace"; "arm, hand."—Editor's note.)

Test for Exactitude

"Two class experiments belonged rather to the periphery of psychology.

"The exactitude of space-perceptions was measured by demanding that each divide first the long and then the short edge of a folio sheet into two equal halves by a pencil-mark.

Test for Rapidity of Movement

"And finally, to measure the rapidity of movement, it was demanded that every one make with a pencil on the paper zigzag movements of a particular size during the ten seconds from one signal to another.

"After these class experiments, I turned to individual tests.