What best describes an "operational definition"?

An operational definition is essentially a clear description of how variables are measured or manipulated in a study. This definition is crucial in research as it allows researchers to quantify abstract concepts, ensuring that variables are consistently treated throughout the study. By specifying how each variable will be observed or measured, operational definitions help enhance the reliability and validity of the research findings. This precision enables other researchers to replicate the study effectively, an essential aspect of the scientific method.

In contrast, a summary of past research on a topic would represent a literature review rather than an operational definition, which highlights how specific elements of the study will be implemented. A theoretical framework is different in that it provides the underlying principles or theories that guide the research, rather than detailing the specific measurement of variables. Meanwhile, guidelines for ethical research practices relate to ensuring the welfare of participants and integrity in research rather than operationalizing variables. Thus, the selected answer appropriately captures the essence of what an operational definition is.