An operational definition specifies how a concept is measured or manipulated within a particular study. It translates abstract theoretical constructs into concrete, observable procedures. For instance, “intelligence” might be operationally defined as the score obtained on a specific standardized IQ test, while “stress” could be quantified by measuring levels of cortisol in saliva.
The value of employing clear definitions lies in enhanced research reproducibility and communication. When researchers explicitly state how variables are measured, others can replicate the study more accurately and interpret the findings with greater confidence. This fosters a more rigorous and transparent scientific process. Historically, vagueness in defining key concepts has hindered progress in various fields, highlighting the necessity of precise, measurable definitions.