What role does manipulation play in experimental research?

Manipulation in experimental research refers to the deliberate alteration of the independent variable by the researcher to observe the effects on a dependent variable. This process is crucial for establishing a cause-and-effect relationship because it enables researchers to isolate the specific effects of the independent variable. By manipulating one factor while controlling others, the researcher can demonstrate how changes in the independent variable directly influence changes in the dependent variable. This helps in assessing the impact of specific variables and supports the fundamental goal of experimental research, which is to determine how variations in one element cause variations in another.