A controlled experiment is one that
A) proceeds slowly enough that a scientist can make careful records of the results.
B) tests experimental and control groups in parallel.
C) is repeated many times to make sure the results are accurate.
D) keeps all variables constant.

Question

Quizplus · Accepted Answer

A controlled experiment includes both experimental and control groups that are tested in parallel under the same conditions except for the variable being tested. This helps to minimize the effects of any confounding variables and allows for a direct comparison between the two groups. The other choices listed also may apply to a controlled experiment, but they do not define what it means to have a controlled experiment.

A Controlled Experiment Is One That