COCHRAN Q TEST 2.2

H = COCHRANQTEST(X) performs the non-parametric Cochran's Q-test on the hypothesis that the K columns of N-by-K matrix have the same number of successes and failures. H==0 indicates that the null hypothesis cannot be rejected at the 5 significance level. H==1 indicates that the null hypothesis can be rejected at the 5% level. X should contain dichotomous values (success/fail, left/right, yes/no, true/false, 0/1, etc.), where one value indicates a success and the other value denotes a failure. The K columns correspond to K related observations; the N rows correspond to N distinct cases. Note that the coding of success and failure does not matter. The highest value will be treated as a success. Also note that cases that comprise only successes or failures do not have an effect on the test statistic.X can be cell array of (two different) strings (e.g., 'YES' and 'NO').H = COCHRANQTEST(...,ALPHA) performs the test at the significance level (100*ALPHA)%. ALPHA must be a scalar between 0 and 1. [H,P] = COCHRANQTEST(...) returns the p-value, i.e., the probability of observing the given result, or one more extreme, by chance if the null hypothesis is true. Small values of P cast doubt on the validity of the null hypothesis. [H,P,STATS] = COCHRANQTEST(...) returns a structure with the following fields: 'Q' -- the value of the test statistic 'df' -- the degrees of freedom of the test 'fail' -- the value regarded as a fail 'pass' -- the value regarded as a success 'Npass' -- the sum of successes for each column 'Ne' -- the number of effective cases (i.e., the number of cases that do show differences on the K observations)COCHRANQTEST(...) without output arguments prints a string saying whether the null-hypothesis should be rejected at significance level APLHA. The Cochran Q test is useful for comparing related samples measured on a categorical (nominal) scale. For K=2 this test equals the McNemar test for two related samples.Version 2.2, okt 2007

Requirements:	No special requirements
Platforms:	Matlab
Keyword:	039df039,  039q039,  Fail,  Fields,  Freedom,  Hpstats,  Regarded,  Structure,  Validity
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