The Minimum Expectation in X 2 Goodness of Fit Tests and the Accuracy of Approximations for the Null Distribution
卡方拟合优度检验的最小期望频数与零假设分布近似精度
The accuracy of approximations for the null distribution of the chi-square goodness of fit statistic, X 2, is examined numerically for many different multinomial distributions. Some of these approximations are terms of a new asymptotic expansion which provides much greater accuracy than the usual χ2 approximation. When there are too many small expectations, even these are inaccurate, and a diflerent type of approximation must be used—the C(m) distribution. It is proven that…