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

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 ...

One is the widely taught Pearson chi-square test, which uses the well-known χ2 statistic. The chi-square test is appropriate for large sample inference, and it is equivalent to the Z-test that uses ...