Contingency tables, also known as cross-tabulation tables, are two-dimensional tables that are used to display the relationship between two or more categorical variables. They are a common tool in data analysis and are used to compare the frequency of occurrence of different variables as well as to explore the relationship between them (Bhargava, 2018). Contingency tables are useful for understanding patterns in data, as well as for hypothesis testing and other statistical analysis.
A contingency table is a matrix that contains the counts of the number of observations in each category of two or more variables. The matrix is typically square, with the rows representing one variable and the columns representing another variable. For example, a contingency table can be used to explore the relationship between gender and smoking, with the rows representing gender and the columns representing smoking. Contingency tables can also be used to compare three or more variables, in which case they are often represented as a rectangular array.
Contingency tables are often used in survey research. For example, they can be used to analyze the responses to a survey by comparing the different responses for each category. Additionally, contingency tables can be used to analyze the relationship between two or more variables, such as the relationship between age and income, or the relationship between gender and political affiliation.
Contingency tables are also commonly used in clinical research to compare the outcomes of different treatments. For example, a contingency table can be used to compare the efficacy of two different medications by looking at the number of patients who experienced the desired outcome with each medication.
Contingency tables are an important tool for data analysis and can be used to help researchers understand the relationship between variables. They are particularly useful for exploring the relationship between two or more categorical variables, and for hypothesis testing.
References
Bhargava, A. (2018). Introduction to Contingency Tables. Retrieved from https://www.statisticshowto.datasciencecentral.com/contingency-table/