In this module, you learned to
- define and apply the scientific method to psychology
- describe the strengths and weaknesses of descriptive, experimental, and correlational research
- define the basic elements of a statistical investigation
Psychologists use the scientific method to examine human behavior and mental processes. Some of the methods you learned about include descriptive, experimental, and correlational research designs.
Watch the CrashCourse video to review the material you learned, then read through the following examples and see if you can come up with your own design for each type of study.
Case Study: a detailed analysis of a particular person, group, business, event, etc. This approach is commonly used to learn more about rare examples with the goal of describing that particular thing.
- Ted Bundy was one of America’s most notorious serial killers who murdered at least 30 women and was executed in 1989. Dr. Al Carlisle evaluated Bundy when he was first arrested and conducted a psychological analysis of Bundy’s development of his sexual fantasies merging into reality (Ramsland, 2012). Carlisle believes that there was a gradual evolution of three processes that guided his actions: fantasy, dissociation, and compartmentalization (Ramsland, 2012). Read Imagining Ted Bundy (http://goo.gl/rGqcUv) for more information on this case study.
Naturalistic Observation: a researcher unobtrusively collects information without the participant’s awareness.
- Drain and Engelhardt (2013) observed six nonverbal children with autism’s evoked and spontaneous communicative acts. Each of the children attended a school for children with autism and were in different classes. They were observed for 30 minutes of each school day. By observing these children without them knowing, they were able to see true communicative acts without any external influences.
Survey: participants are asked to provide information or responses to questions on a survey or structure assessment.
- Educational psychologists can ask students to report their grade point average and what, if anything, they eat for breakfast on an average day. A healthy breakfast has been associated with better academic performance (Digangi’s 1999).
- Anderson (1987) tried to find the relationship between uncomfortably hot temperatures and aggressive behavior, which was then looked at with two studies done on violent and nonviolent crime. Based on previous research that had been done by Anderson and Anderson (1984), it was predicted that violent crimes would be more prevalent during the hotter time of year and the years in which it was hotter weather in general. The study confirmed this prediction.
Longitudinal Study: researchers recruit a sample of participants and track them for an extended period of time.
- In a study of a representative sample of 856 children Eron and his colleagues (1972) found that a boy’s exposure to media violence at age eight was significantly related to his aggressive behavior ten years later, after he graduated from high school.
Cross-Sectional Study: researchers gather participants from different groups (commonly different ages) and look for differences between the groups.
- In 1996, Russell surveyed people of varying age groups and found that people in their 20s tend to report being more lonely than people in their 70s.
Correlational Design: two different variables are measured to determine whether there is a relationship between them.
- Thornhill et al. (2003) had people rate how physically attractive they found other people to be. They then had them separately smell t-shirts those people had worn (without knowing which clothes belonged to whom) and rate how good or bad their body odor was. They found that the more attractive someone was the more pleasant their body odor was rated to be.
- Clinical psychologists can test a new pharmaceutical treatment for depression by giving some patients the new pill and others an already-tested one to see which is the more effective treatment.