What are controlled variables?

What are controlled variables?

• A. Factors that should change during an experiment.
• B. The variables under study that are manipulated.
• C. Factors that should not change during an experiment to ensure meaningful comparisons.
• D. The general conclusions drawn from results.

Answer: (C)

Controlled variables are the factors you keep the same across all parts of an experiment so that any observed effects can be attributed to the factor you are testing. They aren’t the things you’re trying to measure or change; they’re constants that ensure a fair comparison between different conditions (the part you’re testing). For example, if you’re studying how fertilizer affects plant height, you would keep soil type, amount of water, light exposure, and pot size the same for every plant. If these other factors varied, differences in growth could be caused by water or light rather than the fertilizer, making it hard to tell what actually caused any change. The option that says factors should change during an experiment describes the manipulated variable, not what you keep constant. The options describing the variables under study that are manipulated refer to the independent variable, not the constants. The option about conclusions describes the results you draw, not the experimental controls.

Controlled variables are the factors you keep the same across all parts of an experiment so that any observed effects can be attributed to the factor you are testing. They aren’t the things you’re trying to measure or change; they’re constants that ensure a fair comparison between different conditions (the part you’re testing).

For example, if you’re studying how fertilizer affects plant height, you would keep soil type, amount of water, light exposure, and pot size the same for every plant. If these other factors varied, differences in growth could be caused by water or light rather than the fertilizer, making it hard to tell what actually caused any change.

The option that says factors should change during an experiment describes the manipulated variable, not what you keep constant. The options describing the variables under study that are manipulated refer to the independent variable, not the constants. The option about conclusions describes the results you draw, not the experimental controls.