TY - JOUR
T1 - Skew and internal consistency
AU - Greer, Tammy
AU - Dunlap, William P.
AU - Hunter, Samuel T.
AU - Berman, Mitchell E.
PY - 2006/11
Y1 - 2006/11
N2 - The effects of skew on the standardized item alpha were examined with Monte Carlo techniques. Alphas computed from normal variables were compared with alphas from lognormal variables, ranks, and skewed versus normal Likert-type variables. The extent and direction of skew were varied, as was the size of the population interitem correlation (rho), the number of items, and the number of categories for Likert-type variables. Because the average interitem correlation affects alpha and skew affects the average interitem correlation, the effect of skew on the average interitem correlation also was examined. Results indicated that skew decreased the average interitem correlation and produced small decreases in alpha that were largest when skew was large, rho was small, items were skewed in opposite directions, and there were fewer items. (PsycINFO Database Record (c) 2006 APA, all rights reserved).
AB - The effects of skew on the standardized item alpha were examined with Monte Carlo techniques. Alphas computed from normal variables were compared with alphas from lognormal variables, ranks, and skewed versus normal Likert-type variables. The extent and direction of skew were varied, as was the size of the population interitem correlation (rho), the number of items, and the number of categories for Likert-type variables. Because the average interitem correlation affects alpha and skew affects the average interitem correlation, the effect of skew on the average interitem correlation also was examined. Results indicated that skew decreased the average interitem correlation and produced small decreases in alpha that were largest when skew was large, rho was small, items were skewed in opposite directions, and there were fewer items. (PsycINFO Database Record (c) 2006 APA, all rights reserved).
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U2 - 10.1037/0021-9010.91.6.1351
DO - 10.1037/0021-9010.91.6.1351
M3 - Article
C2 - 17100489
AN - SCOPUS:33750994921
SN - 0021-9010
VL - 91
SP - 1351
EP - 1358
JO - Journal of Applied Psychology
JF - Journal of Applied Psychology
IS - 6
ER -