Accession Number : AD0467965

Title :   A GRAPHIC METHOD FOR DETERMINING THE MEAN DIFFERENCE REQUIRED FOR SIGNIFICANCE IN BISERIAL ITEM ANALYSIS.

Descriptive Note : Research rept.,

Corporate Author : NAVAL SCHOOL OF AVIATION MEDICINE PENSACOLA FLA

Personal Author(s) : Lockman,Robert F.

Report Date : 15 MAR 1955

Pagination or Media Count : 3

Abstract : Although graphic methods have been devised for the rapid calculation of biserial (and point biserial) correlation coefficients by the mean difference between dichotorous groups (e. g., pass and fail) can be evaluated by determining biserially thfinitial discriminating ability of any test item. Accordingly, a nomograph was constructed from which the mean differences necessary for biserial significance at the 5 and 10 per cent leels can be obtained with 36 to 200 cases and several dichotomous cuts. A K value, the ratio of the biserial standard error to pq/y, was computed for both significance levels in conjunction with p values of 0.5, 0.7, 0.8, and 0.9 and Ns of 36, 64, 100, 150, and 200. The nomograph can also be used when knowledge of the mean difference required for significane is desired in any biserial analysis. (Author)

Descriptors :   (*PSYCHOLOGICAL TESTS, NOMOGRAPHS), (*NOMOGRAPHS, PSYCHOLOGICAL TESTS), NAVAL TRAINING, PILOTS, CORRELATION TECHNIQUES, STATISTICAL ANALYSIS

Distribution Statement : APPROVED FOR PUBLIC RELEASE