Question

A scientist testing whether caffeine influences memory would likely manipulate the dosage of caffeine in her study. Some individuals would receive a dose of caffeine, while others would receive a placebo. In this type of study, the amount of caffeine is the ________.

1) independent variable.
2) random variable.
3) dependent variable.
4) confounding variable.

Answer 1

In the experiment about caffeine's impact on memory, the dosage of caffeine is the independent variable, which is manipulated by the researcher, while memory is the dependent variable, measured to see the effects of the caffeine.

Step-by-step explanation:

In a scientific study testing the influence of caffeine on memory, the dosage of caffeine given to participants is the independent variable. This is because it is the variable that the scientist manipulates to observe the effects on memory, which in this case, is the dependent variable. The dependent variable is what the researcher measures to see how much effect the independent variable had. In contrast, a placebo is used to control for the effects that participant expectation might have on the experiment, which is a different aspect of experimental design aimed at reducing bias.