A researcher is interested in the effects of monetary incentives on task performance. She recruits 60 undergraduate business students and offers to pay them each $5 for a 1 hour research session. She then randomly assigns these students to either a control group or an incentive group. Participants in both groups try to solve as many anagrams (word puzzles) as they can in 10 minutes. Before the anagram test, participants in the incentive group are told: “On average participants have been able to correctly complete 20 anagrams; you will receive $1 for each anagram more than this average that you are able to correctly complete.” Participants in the control group are not offered this monetary incentive. Instead, they are simply told: “Do your best to correctly complete as many anagrams as you can.” The incentive group correctly solved an average of 29 anagrams and the control group correctly solved an average of only 20 anagrams. The researcher concluded that monetary incentives improved performance over instructions to do your best.

Question

A researcher is interested in the effects of monetary incentives on task performance. She recruits 60 undergraduate business students and offers to pay them each $5 for a 1 hour research session. She then randomly assigns these students to either a control group or an incentive group. Participants in both groups try to solve as many anagrams (word puzzles) as they can in 10 minutes. Before the anagram test, participants in the incentive group are told: “On average participants have been able to correctly complete 20 anagrams; you will receive $1 for each anagram more than this average that you are able to correctly complete.” Participants in the control group are not offered this monetary incentive. Instead, they are simply told: “Do your best to correctly complete as many anagrams as you can.” The incentive group correctly solved an average of 29 anagrams and the control group correctly solved an average of only 20 anagrams. The researcher concluded that monetary incentives improved performance over instructions to do your best.

what is the independent variable?
what are the levels of the independent variable?
what is the dependent variable?
identify one confounding variable?

Answer 1

The independent variable in this study is the presence or absence of monetary incentives.

The levels of the independent variable are the control group (absence of incentives) and the incentive group (presence of incentives).
The dependent variable in this study is task performance, specifically the number of anagrams correctly solved.
One potential confounding variable could be the prior experience or skill level of the participants with solving anagrams.

Answer 2

The independent variable in this study is the presence of monetary incentives.

The levels of the independent variable are the control group (no monetary incentives) and the incentive group (offered monetary incentives).

The dependent variable in this study is the number of correctly solved anagrams.

One potential confounding variable in this study could be the prior experience or skill level with anagrams of the participants. If the control group happened to have a higher proportion of participants who were already skilled at solving anagrams, this could explain their higher performance compared to the incentive group, instead of the absence of monetary incentives.