Understanding the Differences Between Constructs, Variables, and Operational Definitions
One of the most tedious portions of the methodology chapter is describing the constructs, variables, and operational definitions. This section often confuses students because the three ideas seem to overlap. While these ideas are directly connected, they also have unique applications.
Constructs are broad concepts or topics for a study. Constructs can be conceptually defined in that they have meaning in theoretical terms. They can be abstract and do not necessarily need to be directly observable. Examples of constructs include intelligence or life satisfaction.
Variables and operational definitions go hand in hand. Operational definitions specifically identify how the variables are measured for the purposes of the research. An operational definition should identify how the variable is calculated or recorded as a numeric value. In addition, the operational definition should specify the range of possible values and the variable’s level of measurement (nominal, ordinal, or interval). An example of an operational definition for depression would be “the sum of the responses to the Beck Anxiety Inventory, which can range from 0 to 63.”