Which variable is intentionally manipulated in an experimental study?

In an experimental study, the independent variable is the factor that researchers intentionally manipulate to observe its effects on another variable, known as the dependent variable. The manipulation of the independent variable allows researchers to establish cause-and-effect relationships by providing insight into how changes to this variable influence outcomes.

For example, if a researcher is studying the effect of different amounts of sunlight on plant growth, the amount of sunlight is the independent variable. By altering this factor across different groups while measuring plant growth (the dependent variable), the researcher can draw conclusions about the relationship between sunlight exposure and growth rates.

In contrast, the dependent variable is the outcome that is measured in response to the changes made to the independent variable. Controlled variables are conditions kept constant to ensure that the test results are valid and specific to the changes made in the independent variable. Confounding variables are external factors that may influence the outcome of the experiment, and researchers typically aim to minimize or control these variables to avoid biased results.