What is the primary role of independent variables in experiments?

The primary role of independent variables in experiments is to be manipulated for results. This means that the researcher intentionally changes or alters these variables to observe the effects on the dependent variable. By doing this, researchers can establish cause-and-effect relationships between the independent variable and the outcome they are measuring.

For example, if a researcher is studying the impact of different amounts of sunlight on plant growth, the amount of sunlight (the independent variable) can be adjusted to see how it affects the growth of the plants (the dependent variable). The ability to manipulate the independent variable is crucial for experimental design, as it allows for controlled comparisons that can lead to reliable conclusions about causal relationships.

The other options do not accurately represent the function of independent variables. While measuring outcomes relates to dependent variables, remaining constant is characteristic of control variables that help isolate the effects of the independent variable. Introducing bias is not a desired trait in experiment design but rather something researchers strive to minimize to enhance the validity of their findings.