Final answer:
Researchers use operational definitions to ensure that sociological studies are systematic, reliable, and valid when reviewing scientific literature.
Step-by-step explanation:
When conducting a review of literature using the scientific method of studying sociology, researchers develop an operational definition of each concept under study. This is important because it defines the concept in terms of the physical or concrete steps it takes to objectively measure it, ensuring that researchers can collect data in a systematic or replicable manner. The operational definition identifies an observable condition of the concept and establishes clear criteria for measurement, which supports the consistency and replicability of the study. To ensure the accuracy, reliability, and validity of their research, sociologists carefully apply these definitions to study phenomena in a methodical way.