How is a controlled variable different from a responding variable? A. A controlled variable changes due to changes in the responding variable during the experiment. B. A controlled variable stays the same due to changes in the responding variable during the experiment. C. A controlled variable changes throughout an experiment, but a responding variable stays the same. D. A controlled variable stays the same throughout an experiment, but a responding variable changes.
The Correct Answer and Explanation is:
The correct answer is D. A controlled variable stays the same throughout an experiment, but a responding variable changes.
Explanation:
In an experiment, variables play specific roles to help researchers understand the relationships between them. The two key types of variables in an experiment are controlled variables and responding variables.
- Controlled Variable:
A controlled variable (also called a constant or independent variable) is a factor that the experimenter deliberately keeps the same throughout the experiment. These are variables that could potentially affect the outcome of the experiment but are not the focus of the investigation. By keeping them constant, researchers ensure that the results are not influenced by changes in factors other than the variable being tested. For example, in an experiment on plant growth, the temperature and type of soil might be controlled variables, as they are kept constant to avoid affecting the growth of the plants in ways unrelated to the variable being tested (such as water or light). - Responding Variable:
The responding variable (also called the dependent variable) is the variable that is measured or observed in response to changes in the independent (manipulated) variable. The responding variable depends on the changes made to the independent variable. In the plant growth experiment, the height of the plants might be the responding variable because it changes depending on the amount of water, light, or other factors that are being tested.
Key Difference:
- The controlled variable does not change and is kept constant throughout the experiment.
- The responding variable changes as a direct result of the experimental manipulation (i.e., changes in the independent variable).
This distinction ensures that the experiment remains reliable and valid, allowing the researcher to isolate the effects of the manipulated variables.
