What is a dependent variable?

A dependent variable is fundamentally defined as the factor that researchers measure in response to changes made to the independent variable. Within the context of an experiment, the independent variable is what the researcher manipulates, while the dependent variable is expected to change as a result of this manipulation. This relationship allows researchers to assess the effect of the independent variable on the dependent variable.

In an experimental setup, understanding this relationship is crucial for drawing conclusions about causality. For example, if a researcher is studying how different amounts of sunlight affect plant growth, the growth of the plants (which can be measured by height, number of leaves, or biomass) is the dependent variable. It is directly affected by the changes made to the amount of sunlight the plants receive.

Other choices refer to different aspects of experimental design. One option describes a variable that is altered by the researcher, which refers to the independent variable rather than clarifying the role of the dependent variable. Another option talks about a controlled variable, which is essential for reducing bias but does not convey the relationship of dependency involved. The last choice pertains to a definition relevant for the experimental setup rather than specifying the dependent variable itself. Therefore, the correct choice captures the essence of what a dependent variable is and its role in research.