Research Methods

Identifying Threats to Internal Validity

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Directions: For the brief descriptions below, identify which threats to internal validity are possible. You may not agree with the researcher's conclusion, but that is not the point here. The point is that there can be problems with the design of a study that interfere with our confidence in the validity of the results. Make sure you say why you think the threat is likely to affect the results. Remember that in identifying such threats, we don’t know if the potential problems actually affect the results; we can only try to identify them. We can then use subsequent replications to see if the possible threats actually affect the results.

1. Researchers have studied people orientation toward success by giving them scenarios such as one in which women are told that Jane is studying for a test and men are told that John is studying for a test. Then the research participants have to complete the story. Results suggest that woman create stories that are less oriented toward success than men do. The researchers concluded that women show a fear of success.


2. Two psychologists investigated the relation between playing action video games and the ability to monitor the visual environment. They recruited a group of male undergraduates who played action video games at least one hour a day, four days a week over the previous six months. A control group of non-video game players also participated in the study.

The researchers discovered that video game players were better at monitoring visual elements unrelated to the video game while they were playing the game. The researchers concluded that playing video games increases one’s capacity to pay attention to details in a visual environment.

Green, C. S., & Bavelier, D. (2003). Action video game modifies visual selective attention. Nature, 423, 534-537.


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Last updated March 5, 2012