What is the factor in an experiment that is manipulated to observe its effects?

In an experiment, the factor that is manipulated to observe its effects is known as the independent variable. This variable is the one that researchers change or control in order to determine how it impacts another variable, often referred to as the dependent variable. By adjusting the independent variable, researchers can observe any resulting changes in the dependent variable, which helps establish cause-and-effect relationships in the study.

For example, if a researcher is investigating how varying levels of study time (the independent variable) affect test scores (the dependent variable), they might assign different groups of participants to study for different amounts of time and then measure their test performance. The independent variable is integral to this process, as it allows researchers to draw conclusions about the influence of one factor on another.