Which of the following best describes a controlled experiment?

Question

A. An experiment that includes one group for which the scientist controls all variables
B. An experiment includes at least two groups, one of which does not receive the experimental treatment
C. An experiment that includes at least two groups, one differing from the other by two or more variables
D. An experiment repeated many times to ensure that the results are accurate

Answer 1

The option that best describes a controlled experiment is:

B. An experiment includes at least two groups, one of which does not receive the experimental treatment.

In a controlled experiment, typically there is a control group (which does not receive the treatment) and an experimental group (which does receive the treatment). This allows for comparison to determine the effect of the experimental treatment while controlling for other variables.