II.
Method of Identification.] Briefly described in words, it was found that the three methods agreed (the curves are parallel)[8] in showing that during the first ten minutes there was a great falling off in the accuracy of memory (slant in the curves from 0 to 10); that then, between ten and twenty minutes, memory remained relatively faithful (the curves are nearly level from 10 to 20), and that a rapid falling off in accuracy occurred after twenty minutes (shown by the slant in the lines from 20 to 40).
[Footnote 8: This figure shows curves for two of the methods only, Selection and Identification.] Further, the different positions of the curves show certain things when properly understood.

The curve secured by the method of Reproduction (not given in the figure) shows results which are least accurate, because most variable.

The reason of this is that in drawing the squares to reproduce the one remembered, the student is influenced by the size of the paper he uses, by the varying accuracy of his control over his hand and arm (the results vary, for example, according as he uses his right or left hand), and by all sorts of associations with square objects which may at the time be in his mind.
In short, this method gives his memory of the square a chance to be fully assimilated to his current mental state during the interval, and there is no corrective outside of him to keep him true.
That this difficulty is a real one no one who has examined students will be disposed to deny.

When we ask them to reproduce what the text-book or the professor's lectures have taught, we also ask them to express themselves accurately.

Now the science of correct expression is a thing in which the average student has had no training.