Experiments: Practice identifying independent and dependent variables (Part 2)

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Last week, I gave five examples of experiments you can use to give students practice at identifying independent and dependent variables. Here are five more.

After covering these concepts, ask students to work in pairs or small groups to identify both the independent variable(s) and the dependent variable(s) in each example.

Hypothesis: If people use third person pronouns to describe an event that caused anxiety, they will be more likely to report visualizing the scene as a distant observer would.

Researchers asked study participants to recall a time when they were “worried about something happening to” them. Participants were then randomly assigned to either the first person condition or the third person condition. In the first person condition, participants reflected on their experience through answering questions with an I/my focus, like “Why did I feel this way?” and “What were the underlying causes and reasons for my feelings?” In third person condition, participants reflected on their experience through answering questions with an outsider’s focus by using their own name in their reflection, like “Why did Jane feel this way?” and “What were the underlying causes and reasons for Jane’s feelings?” When asked, participants in the third-person group reported seeing the imagined event unfold further away from them than reported by participants in the first-person group.

In this experiment, identify the independent variable and the dependent variable. 

Kross, E., Bruehlman-Senecal, E., Park, J., Burson, A., Dougherty, A., Shablack, H., … Ayduk, O. (2014). Self-talk as a regulatory mechanism: How you do it matters. Journal of Personality and Social Psychology, 106(2), 304–324. https://doi.org/10.1037/a0035173

Hypothesis: If people hear how many others who stayed in their hotel room chose to reuse their hotel room towels, they will be more likely to reuse their towels, too.

 The hotel room attendant supervisor placed one of five signs in the bathrooms of randomly-assigned hotel rooms. Each sign carried a different message: (1) a general “save the environment” message, (2) a “join your fellow guests” message explaining that 75% of guests who stayed at the hotel reused their towels, (3) another “join your fellow guests” message but this one explained that 75% of people who stayed in that very hotel room reused their towels, (4) a “join your fellow citizens” message that shifted the in-group from hotel guests to the broader citizens, and (5) a “join the men and women” message that shifted the in-group to one’s own gender group. Hotel guests who received message 3 about others who stayed in their hotel room were much more likely to reuse their towels (49.3%) as compared to all of the other groups (average re-use 42.8%).

In this experiment, identify the independent variable and the dependent variable. 

Goldstein, N. J., Cialdini, R. B., & Griskevicius, V. (2008). A room with a viewpoint: Using social norms to motivate environmental conservation in hotels. Journal of Consumer Research, 35(3), 472–482. https://doi.org/10.1086/586910

Hypothesis: If people are given unwrapped pieces of chocolate, they will consume them more quickly than those given wrapped pieces of chocolate.

Participants received six pieces of chocolate. Random assignment determined which participants received separately wrapped pieces and which received unwrapped pieces. Participants were asked to record when they ate the chocolate. Those who received the unwrapped pieces ate most of them within two days. Those with wrapped pieces took longer.

In this experiment, identify the independent variable and the dependent variable. 

Cheema, A., & Soman, D. (2008). The effect of partitions on controlling consumption. Journal of Marketing Research, 45(6), 665–675. https://doi.org/10.1509/jmkr.45.6.665Use the "Insert Citation" button to add citations to this document.

Hypothesis: If people receive information about available health services, they will use those services more.

Researchers sampled several communities in India on their use of available health services. They randomly assigned half of the communities to receive pamphlets and community meetings that informed them of services. A year later, these residents had more prenatal examinations, more tetanus vaccinations, more prenatal supplements, and more infant vaccinations than people in the communities that did not receive the pamphlets or hold the community meetings.

In this experiment, identify the independent variable and the dependent variables.

Pandey, P., Sehgal, A. R., Riboud, M., Levine, D., & Goyal, M. (2007). Informing resource-poor populations and the delivery of entitled health and social services in rural India: A cluster randomized controlled trial. Journal of the American Medical Association, 298(16), 1867–1875. https://doi.org/10.1001/jama.298.16.1867

Hypothesis: If we invite girls to “do science” as compared to “be a scientist,” they will persist longer in playing a science game.

Researchers randomly assigned young girls to hear that “Today we’re going to do science” or hear that “Today we’re going to be scientists” before playing a science game where the children had to make guesses based on observation. After failing at their guesses, the experimenter the child if she wanted to keep playing or do something else. The girls in the “do science” condition were more likely to persist in playing the game than those in the “be a scientist” condition.

In this experiment, identify the independent variable and the dependent variable.

Rhodes, M., Leslie, S. J., Yee, K. M., & Saunders, K. (2019). Subtle linguistic cues increase girls’ engagement in science. Psychological Science. https://doi.org/10.1177/0956797618823670