A chi-square (χ2) statistic is a test that is used to measure how expectations compare to actual observed data or model results.

The Pearson chi-square provides evidence of an association between eye and hair color (p=.007). The cell chi-square values show that most of the association is due to more green-eyed children with ...

The chi-square test, likelihood ratio test, and other goodness of fit tests in a family are shown to have monotonic power functions, and hence are unbiased, for testing a simple hypothesis that all ...