Cosella is conducting an experiment where she assesses how quickly teenagers can run a 100-meter race after consuming specific amounts of caffeine. She divides her sample up into three groups. Group 1 receives a glass of water (zero caffeine). Group 2 receives the equivalent of the caffeine in one cup of coffee. Group 3 receives the equivalent of two cups of coffee. Each participant is then timed as they run the course. In this study, the dependent variable is
A) the previous running experience of each participant.
B) the teenagers who are being studied.
C) the time it takes to run the 100-meter race.
D) the amount of caffeine being ingested.

Question

Quizplus · Accepted Answer

The dependent variable in this study is the time it takes to run the 100-meter race. This is what is being measured and compared between the three groups who received different amounts of caffeine. The independent variable is the amount of caffeine being ingested, as this is what is being manipulated by the researcher. The previous running experience of each participant and the teenagers being studied are not the variables of interest in the study.

Cosella Is Conducting an Experiment Where She Assesses How Quickly