What does it mean to operationally define a variable?

Operationally defining a variable involves specifying the exact procedures that will be used to measure or manipulate it within the context of a study. This definition is crucial because it allows researchers to ensure that everyone understands what is being investigated and how it will be assessed. For example, if a variable is "stress," an operational definition might specify that stress will be measured using a particular questionnaire or physiological markers, such as cortisol levels. By outlining these procedures, researchers can replicate the study and examine the variable in a consistent manner across different contexts or experiments, enhancing the validity and reliability of the findings.

In contrast, providing a theoretical concept would not specify how the variable is measured, and categorizing the variable into qualitative data does not reflect the measurement or manipulation aspect inherent in operational definitions. Summarizing findings related to the variable is an analysis step that comes after data has been collected and does not pertain to the definition of the variable itself.