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

Question

Quizplus · Accepted Answer

A controlled experiment involves manipulating one variable while keeping all other variables constant. In order to establish cause and effect, the experiment should include both experimental groups (which receive the manipulated variable) and control groups (which do not receive the manipulated variable) tested in parallel. This allows for comparison and ensures that any observed effects are due to the manipulated variable and not other factors. The other options listed (A, C, D, E) are not necessarily specific to controlled experiments but may apply to scientific experimentation in general.

A Controlled Experiment Is One That