A researcher wants to assess the effect of sleep on test performance. She brings students into the lab, gives each student an IQ test, and then asks them how much they slept last night. This would NOT be an experiment because
A)IQ was measured first
B)sleep was measured second
C)sleep and IQ were measured at the same time
D)no variable was manipulated

Question

Quizplus · Accepted Answer

The key aspect of an experiment is the manipulation of an independent variable to observe its effect on a dependent variable. In this scenario, the researcher did not manipulate how much sleep the students got; she merely recorded it. Thus, it's not an experiment because there's no manipulation of variables.

A Researcher Wants to Assess the Effect of Sleep on Test