In an experimental study, men with erectile disorder received either Viagra or a placebo. In this study, the drug dosage (none versus peak dose) was the
A) confounding variable.

B) dependent variable.

C) random sample.

D) independent variable.

Question

In an experimental study, men with erectile disorder received either Viagra or a placebo. In this study, the drug dosage (none versus peak dose) was the
A) confounding variable.

B) dependent variable.

C) random sample.

D) independent variable.

justjm · Answer

It seems like the study wants to measure the effectiveness of Viagra to a relative level. So it's changing the drug dosage from 0 (a placebo to avoid bias) to peak dose.

What's being changed is drug dosage, so what do you think? Recall independent variable is what you change. A random sample is a statistical term where an SRS is taken out of a population. Dependent variable is what you measure. Confounding variable is an unintentional factor that skews results and creates bias in a study.