The variable that is varied or manipulated by the researcher is the ...

The variable that is varied or manipulated by the researcher is the ...

• A. Dependent Variable
• B. Positive Control
• C. Independent Variable
• D. Negative Control

Answer: (C)

The variable you deliberately change to see its effect is the independent variable. In an experiment, you decide how to vary this factor to observe what happens to the outcome, which is the dependent variable and is what you measure. For example, if you’re testing how different drug doses affect sleep, the dose (or presence/absence of the drug) is the independent variable, and sleep duration is the dependent variable you record. Controls serve different roles: a positive control confirms the experiment would show an effect if one is present, and a negative control shows baseline conditions without the treatment. These controls aren’t the variable you manipulate. They help validate that the observed effects are due to the independent variable.

The variable you deliberately change to see its effect is the independent variable. In an experiment, you decide how to vary this factor to observe what happens to the outcome, which is the dependent variable and is what you measure. For example, if you’re testing how different drug doses affect sleep, the dose (or presence/absence of the drug) is the independent variable, and sleep duration is the dependent variable you record.

Controls serve different roles: a positive control confirms the experiment would show an effect if one is present, and a negative control shows baseline conditions without the treatment. These controls aren’t the variable you manipulate. They help validate that the observed effects are due to the independent variable.