What does the VAR statement in PROC FREQ do?

The VAR statement in PROC FREQ is used to select the variables that you want to analyze for frequency counts. When you include the VAR statement in your PROC FREQ step, you specify which variables should be included in the frequency analysis. This allows SAS to generate frequency tables for the specified variables, showing the distribution of categorical data.

In frequency analysis, it is important to focus on specific variables to get meaningful outputs. For example, if you are analyzing survey data and want to understand how many respondents chose each option for a particular question, you would use the VAR statement to indicate that question's variable.

The other options refer to different functionalities: identifying formats relates to formatting capabilities within SAS, grouping by categories may pertain to other procedures or statements designed for analysis by groups, and defining the data set is a function of the PROC step, not specifically encapsulated in the VAR statement itself. Thus, the primary function of the VAR statement revolves around selecting the specific variables for summarization in PROC FREQ.