What characteristic does a variable have in research studies?

In research studies, a variable is defined as any characteristic or attribute that can vary among subjects or over time. For a variable to be useful in research, it must have the capacity to change, which allows researchers to assess relationships, effects, or differences. Additionally, a variable must be measurable in order to gather data and analyze it meaningfully. Measuring a variable enables researchers to quantify their findings, draw conclusions, and make inferences based on the data collected. This is foundational in conducting empirical research, as the ability to observe and measure change directly informs the study's outcomes and validity.

The emphasis on both changeability and measurability ensures that researchers can formulate hypotheses and test them effectively, thereby contributing to the body of knowledge in their field.