A variable is anything that can take on differing or varying values. The values can differ at various times for the same object or person, or at the same time for different objects or persons. Examples of variables are production units, absenteeism, and motivation.
Four main types of variables are discussed in this chapter:
- The dependent variable (also known as the criterion variable).
- The independent variable (also known as the predictor variable).
- The moderating variable.
- The mediating variable.
Each of these variables can be discrete (e.g., male/female) or continuous (e.g., the age of an individual).
Dependent Variable
The dependent variable is the variable of primary interest to the researcher. The researcher’s goal is to understand and describe the dependent variable, or to explain its variability, or predict it. It is the variable that is being influenced by other variable(s).
Independent Variable
Independent variable is one that influences the dependent variable in either a positive or negative way. That is, when the independent variable is present, the dependent variable is also present, and with each unit of increase in the independent variable, there is an increase or decrease in the dependent variable.
Moderating Variable
A moderating variable is the one that modifies the existing relationship between the independent and dependent variable I-e it holds a strong contingent effect on the association of IV and DV. Modification could mean to strengthen, weaken, or altogether change the direction of relationship.
Mediating Variable
A mediator variable is the variable that causes mediation in the dependent and the independent variables. In other words, it explains the relationship between the dependent variable and the independent variable. The variable that explains the mechanism of impact of IV on DV is referred to as a mediator. When we say that the impact of IV on DV is not direct, and it is through another variable(s), that third variable is the mediator. Simply mean the IV affect the MV and that leads to the DV. What we are in simple term saying is that IV does not affect the DV directly, but it is actually the IV affecting the MV and that in turn affect the DV.