An approximation to the distribution of the X2 goodness-of-fit statistic for use with small expectations

@article{Lawal1980AnAT,
title={An approximation to the distribution of the X2 goodness-of-fit statistic for use with small expectations},
author={H. Lawal and G. Upton},
journal={Biometrika},
year={1980},
volume={67},
pages={447-453}
}

SUMMARY This paper is concerned with the X2 goodness-of-fit test when the observed frequencies are supposed to be distributed according to a specified multinomial distribution. We propose a log normal approximation to the distribution of X2. Our results suggest that the approximation is valid providing that the smallest expectation is greater than r/d3/2, where r is the number of expectations less than 5, and d is the number of degrees of freedom.