This m-file performs the Bowker's test for symmetry. It is an extension of the McNemar test to a KxK situation. There are now K response categories for the two dependent samples.
The null hypothesis is that the probabilities in the square table satisfy symmetry or that there is no sifnificant shift from one response category to another from sample 1 to sample 2.
When the null hypothesis of symmetry is true, then B will have a Chi-square distribution with K(K-1) degrees of freedom. This is the basis of the proposed test by Bowker (1948). If K=2, then B simplifies to the McNemar test statistic.
It need to input X-data matrix defined by the KxK observed frequency cells, t-desired test [t = 1, one-tail; t = 2, two-tail (default)], and alpha-significance level (default = 0.05).
The output is a table with the proportion of success for the dependent samples and the P-values using and not correction for discontinuity. |
