Answer: The factors that can change value during an experiment or between experiments, such as water temperature, are called variables, while those that stay the same, such as acceleration due to gravity at a certain location, are called constants.

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Definition of a Control Group A control group is a set of experimental samples or subjects that are kept separate and aren’t exposed to the independent variable. A controlled experiment is one in which every parameter is held constant except for the experimental (independent) variable.

There must be an independent variable, which changes throughout the course of an experiment; a dependent variable, which is observed and measured; and a controlled variable, also known as the “constant” variable, which must remain consistent and unchanging throughout the experiment.

A confounding variable is a condition that is not held constant that could affect the experimental results.

The difference between Constant and Control is that a constant variable does not change throughout an experiment. A control variable, on the other hand, can change but is deliberately kept constant to isolate the interrelation between an independent variable and a dependent variable.

A control group is a group separated from the rest of the experiment such that the independent variable being tested cannot influence the results. This isolates the independent variable’s effects on the experiment and can help rule out alternative explanations of the experimental results.

A positive control group is a control group that is not exposed to the experimental treatment but that is exposed to some other treatment that is known to produce the expected effect. These sorts of controls are particularly useful for validating the experimental procedure.