Cell chisquare test
The cell chisquare test looks at each table cell and tests whether it is significantly different from its expected value in the overall table. For example, if it is thought that variations in political opinions might depend on the respondent's age, this test can be used to detect which cells contribute significantly to that dependence.
Unlike the chisquare test, which is carried out on a whole set of rows and columns, the cell chisquare test is carried out independently on each table cell. This is done by treating each cell as belonging to a twobytwo table, known as a contingency table, as follows:

Base

In column

Not in column

Base

B

C

BC

In row

R

V

RV

Not in row

BR

CV

BRC+V

For each cell, the values B, C, R and V are taken from the table. The other values are calculated from these values.
The formula applied to this twobytwo table is the standard Pearson chisquare formula, with the Yates' correction for small samples when relevant as the p value associated with the Pearson chisquare test can be distorted if any cells in the table have very low expected counts (below 5).
Although the significance level of the cell chisquare test is accurate for any given cell, the cell tests cannot be used instead of the chisquare test carried out on the overall table. Their purpose is simply to point to the parts of the table where dependencies between row and column categories might exist.
See also