2uData ⮞Data Description ⮞Contingency tables

Contingency tables

Contingency table, also known as cross tabulation or crosstab or two-way table, is used to express the relation between two variables (generally nominal ones). To clarify this concept, let's examine an example.

Example 3 : In order to understand the preference of consumers, a survey was conducted with 200 people. They are separated into 3 groups based on their income: High, Intermediate, and Low. There are two types of product: Meat product and Fruit product. The result of this survey is shown in Table 1.

Table 1 Result of marketing research on preference and income of consumers

	High income	Intermediate income	Low income	Total
Meat product	18	42	58	118
Fruit product	42	28	12	82
Total	60	70	60	200

From Table 1, we know that there are 200 consumers participating in the research, in which:

• 118 consumers prefer meat product,
• 70 consumers belong to the group of intermediate income,
• 42 consumers in the group of high income prefer fruit product,
• 58 consumers in the group of low income prefer meat product,
• . . . .

Hence, besides the last column (Total) and the last row (Total), the value in a cell in the contingency table is the number of elements corresponds to the value of column variable and the value of row variable. For example, 42 is the number of consumers in the intermediate income group that prefer meat product.