When cochrans q test is computed with only k 2 groups, the results are equivalent to those obtained from the mcnemar test without continuity correction. Spss cochran q test is a procedure for testing if the proportions of 3 or more dichotomous variables are equal in some population. Cochrans q is also considered to be a special case of the. Cochrans q test is a nonparametric test for anova with repeated measures where the dependent variable is dichotomous. The initial data are represented as a series of k 2x2 contingency table s, where k is the number of strata.
The cochran mantelhaenszel cmh test compares two groups on a binary response, adjusting for control variables. Cochrans test was developed to answer a specific question. Cochranmantelhaenszel test english to spanish medical. The tested data are the minimum and maximum values. Essentially, the cmh test examines the weighted association of a set of 2 \\times\ 2 tables. Cochran s q is also considered to be a special case of the. If x is the score variable, the statistic that is computed to test for the linearity is given by. Using the grubbs and cochran tests to identify outliers. Grubbs test this test detects outliers from normal distributions. This behavior was measured for 20 workers on monday, wednesday and friday during one week in march, as shown in figure 1 where 1. In proficiency testing, john mandels k consistency statistic has been used specifically, the astm e691 standard to identify laboratories with excessively large variances the iso 5725 standard proposes cochrans variance outlier test as. The principal of some university wants to know whether three examns are equally difficult.
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