What is true regarding the relationship of independent and dependent variables in research?

In research, the relationship between independent and dependent variables is foundational to understanding causality. The independent variable is the one that the researcher manipulates or controls, while the dependent variable is the one that is measured to determine the effect of that manipulation. Because of this definition, the independent variable is considered the cause of any changes observed in the dependent variable, which is identified as the effect.

When the independent variable is altered, the researcher observes how this impacts the dependent variable, thereby establishing a cause-and-effect relationship. For instance, if a study examines the effects of a new medication (independent variable) on blood pressure (dependent variable), changes in blood pressure can be directly attributed to adjustments made in the medication dosage. Understanding this relationship helps researchers draw valid conclusions and build reliable evidence in scientific inquiries.