In a controlled experiment, which statement accurately describes the independent and dependent variables?

In a controlled experiment, which statement accurately describes the independent and dependent variables?

• A. The independent variable is deliberately changed by the researcher; the dependent variable is the measurement observed.
• B. The dependent variable is deliberately changed; the independent variable is the observation recorded.
• C. Both variables are kept constant throughout the experiment.
• D. The dependent variable is the instrument used to measure results.

Answer: (A)

In a controlled experiment, you deliberately change the factor you think will influence the outcome and then observe what happens by measuring another factor you expect to respond. The factor you set or adjust is the independent variable, and the thing you measure to see the effect is the dependent variable. So, the independent variable is what the researcher changes on purpose, and the dependent variable is the observation or measurement that shows the result of that change. Other variables are kept the same so any observed effect can be attributed to the manipulation of the independent variable. This matches the described statement because it correctly identifies the independent variable as being deliberately changed and the dependent variable as the measurement observed. If the dependent variable were the one changed, that would invert the intended role of the variables. If both were kept constant, nothing would be tested. If the dependent variable were just the instrument used to measure results, the instrument isn’t the variable being tested—it's the tool for measurement.

In a controlled experiment, you deliberately change the factor you think will influence the outcome and then observe what happens by measuring another factor you expect to respond. The factor you set or adjust is the independent variable, and the thing you measure to see the effect is the dependent variable.

So, the independent variable is what the researcher changes on purpose, and the dependent variable is the observation or measurement that shows the result of that change. Other variables are kept the same so any observed effect can be attributed to the manipulation of the independent variable.

This matches the described statement because it correctly identifies the independent variable as being deliberately changed and the dependent variable as the measurement observed. If the dependent variable were the one changed, that would invert the intended role of the variables. If both were kept constant, nothing would be tested. If the dependent variable were just the instrument used to measure results, the instrument isn’t the variable being tested—it's the tool for measurement.