About the Book
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1910 edition. Excerpt: ...those devoted to discrimination reactions; the author has tried the test as a measure of fatigue, and also has sought to determine its correlation with class standing.1 The results of the cancellation test are conditioned in the main by three methodological factors--(a) the number of letters to be cancelled, (b) the kind of text or material employed, and (c) the duration of the test. (a) Letters cancelled. It is easily demonstrated that the ranks of a given number of 5's will vary somewhat according as a few (1-2) orseveral letters (4-6) are to be cancelled. Where but one letter has been used, this has commonly been the letter a (Bourdon, Cattell and Farrand, Wissler, Thorndike, Sharp) or occasionally e. In cancelling more than one letter, we find that Bourdon tried at different times, a and i; a, r, i, s; a, e, I, t; or a, c, l, t, o, k; Binet, a, e, d, r, s, also i, o, I, f, t, and a, e, r, o, s, m; Vogt, l, n, s; Winteler n, s, t, and I, m, r, s, t. It is Binet's contention that, when but one letter is cancelled, S'stendto work with approximately equal accuracy, but with varying speed, whereas, when four or five letters are cancelled, they tend to work with approximately equal speed, but with varying accuracy; he, accordingly, arranges the test in one or the other of these ways, as he wishes to measure either speed or accuracy. As will be shown later, this assumption is not strictly justifiable. The cancellation of one letter is so easy that some investigators have tried other devices for complicating the task: Ritter, for example, had his S's cancel every r with a vertical stroke and every article (in German texts) with a horizontal stroke, or, again, every s with a vertical and every preposition with a horizontal stroke: his idea that these...
