• The null hypothesis for tables of count data is that there is no relationship between the row variable and the column variable.
• Expected cell counts under the null hypothesis are computed using the formula
• The null hypothesis is tested by the chi-
Under the null hypothesis, has approximately the distribution with degrees of freedom. The -value for the test is
where is a random variable having the distribution with
.
• The chi-
• For two-
• Two different models for generating tables lead to the chi-