@lochan Welcome to the SAS forum.  Your question is about changing a variable type.    First, please note that typically the usage of the variable is what defines the type, ie categerical variables are included in the CLASS statement, not necessarily the variable type.    SAS has two variable types, character and numeric. You can apply formats to those variables.    If you have a numerical variable, and it has only two levels then it will be treated correctly. If you're using the variable in PROC REG it would need to be numeric anyways, so it's unlikely you need to change the type.   Good Luck with your analysis.    PS. If you search on here, there's been some posts on analyzing the Titanic data in SAS. ... View more