Experiments sometimes include measuring the variable/concept both before and after an intervention of some sort. This technique is known as a

A) cross-sectional testing.
B) primary test and secondary test.
C) pretest and posttest.
D) control and experiment.

The technique described is called a pretest and posttest, where the variable is measured before and after an intervention. Choice A (cross-sectional testing) refers to comparing different populations at the same point in time. Choice B (primary test and secondary test) is not a commonly used term in experimental design. Choice D (control and experiment) refers to the experimental group receiving the intervention and the control group not receiving the intervention.