Contingency Table (Two-way Table)
Contingency Table (Two-way Table) is part of:Contingency table structure
A contingency table is an efficient way to summarize the relation (or correspondence) between two categorical variables V1 and V2. It has the following structure:
| V1 V2 | Category 1 | Category j | … | Category m2 |
| Category 1 | n(1,1) | n(1,j) | … | n(1,m2) |
| … | … | … | … | … |
| Category i | n(i,1) | n(i,j) | … | n(i,m2) |
| … | … | … | … | … |
| Category m1 | n(m1,1) | n(m1,j) | … | n(m1,m2) |
where n(i,j) is the frequency of observations that show both characteristic i for variable V1, and characteristic j for variable V2.
Test on contingency table
XLSTAT provides you with two criteria to characterize the relationship between the two variables:
- The Chi-square distance has been suggested to measure the distance between two categories. The Pearson chi-square statistic, which is the sum of the Chi-square distances, is used to test the independence between rows and columns.
- Inertia is a measure inspired from physics that is often used in Correspondence Analysis, a method that is used to analyse in depth contingency tables. The inertia of a set of points is the weighted mean of the squared distances to the center of gravity.