9. 1 The Nature of Dummy Variables ●1. Concept: Dummy variables(also indicator variables; binary variables categorical variables, dichotomous variables. Qualitative variables in regression model For example: sex, race, color, religion, nationality, marital status. etc Qualitative variables can be quantified by constructing artificial variables that take on values of l or o 0: indicating the absence of an attribute 1: indicating the presence(or possession) of that attribute Dummy variable (D): variables that assume values such aso and9.1 The Nature of Dummy Variables ⚫ 1.Concept: Dummy variables (also indicator variables; binary variables; categorical variables; dichotomous variables.)－－ Qualitative variables in regression model. For example: sex, race, color, religion, nationality, marital status, etc. Qualitative variables can be quantified by constructing artificial variables that take on values of 1 or 0: 0: indicating the absence of an attribute 1: indicating the presence (or possession) of that attribute. Dummy variable（D）: variables that assume values such as 0 and 1