Tables of frequencies for two variables are often called two-way tables, contingency tables, or crosstabs. These are examples of bivariate statistics, or statistics that describe the joint distribution of the two variables. Frequencies for Two Categorical Variablesįor two categorical variables, frequencies tell you how many observations fall in each combination of the two categorical variables (like black women or hispanic men) and can give you a sense of the relationship between the two variables. Means are often called averages, and variance is just the standard deviation squared. Quantitative variables are often called continuous variables.
However, the median and percentiles often give you a better sense of how the variable is distributed, especially for variables that are not symmetric (like income, which often has a few very high values). Summary Statistics for a Single Quantitative Variableįor a variable that describes quantities (like income) the mean tells you what the expected value of the variable is, and the standard deviation tells you how much it varies. Frequency tables for a single variable are sometimes called one-way tables. Indicator variables (also called binary or dummy variables) are just categorical variables with two categories. These are examples of univariate statistics, or statistics that describe a single variable.Ĭategorical variables are also sometimes called factor variables. Topics Covered in this Section Frequencies for a Single Categorical Variableįor a variable that describes categories (like sex or race) rather than quantities (like income) frequencies tell you how many observations are in each category. If you are new to Stata we strongly recommend reading all the articles in the Stata Basics section.ĭescriptive statistics give you a basic understanding one or more variables and how they relate to each other.
This article is part of the Stata for Students series.
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