(Scenario III) In Scenario III the researchers included only those participants who were not regular caffeine drinkers. In doing do, the researchers:
A) increased experimental control.
B) minimized caffeine tolerance as an extraneous variable.
C) increased the internal validity of the study.
D) All of the above.

Question

Quizplus · Accepted Answer

By including only participants who were not regular caffeine drinkers, the researchers increased experimental control by ensuring that all participants had similar caffeine baselines, minimized caffeine tolerance as an extraneous variable which could otherwise affect the results, and increased the internal validity of the study by reducing the potential for confounding variables.

(Scenario III) in Scenario III the Researchers Included Only Those