Case Studies RESEARCH METHODS

Transcription

1 Case Studies RESEARCH METHODS

2 The What Subjects selected based on conditions already present 1. Independent variable already established or "manipulated" by nature a. Not a true independent variable b. Cannot make cause and effect statements about results 2. Most often used because of ethical concerns about alternative methods (e.g., experimental methods)

3 The Why It may be impractical, unethical, or impossible to use the experimental method to study rare events, such as unusual mental disorders, childhood geniuses, or rampage school shootings (Harding, Fox, & Mehta, 2002). A case study is an in-depth focus on a single subject may be the best source of information. Clinical psychologists rely heavily on case studies, especially as a way to investigate mental disorders, such as depression or psychosis. Also, case studies of psychotherapy have provided many useful ideas about how to treat emotional problems (Wedding & Corsini, 2011).

4 For example: A Hearing Child Raised by Deaf Parents Perhaps a psychologist discovers a situation in which two deaf parents have given birth to a hearing child. How would their child develop language? Obviously, the child will learn sign language as a native user, but since the child can hear, the child will also learn to speak. The pattern of the language development might be unique or follow an unusual pattern, but the psychologists cannot wait until there is a reasonable sample of similar children to do a group study. Psychologists also would not wish to conduct experiments that create this situation, and although it would be possible to conduct observations of social interactions and language use by this child, the data would be based only on this child. Thus we have the case study.

5 Case studies may sometimes be thought of as natural clinical tests accidents or other natural events that provide psychological data. Gunshot wounds, brain tumors, accidental poisonings, and similar disasters have provided much information about the human brain.

6 Famous case studies: One remarkable case from the history of psychology was reported by Dr. J. M. Harlow (1868). Phineas Gage, a young foreman on a work crew, had a 13-pound steel rod impaled into the front of his brain by a dynamite explosion. Amazingly, he survived the accident. Within 2 months Gage could walk, talk, and move normally, but the injury forever changed his personality. Instead of the honest and dependable worker he had been before, Gage became a surly, foul-mouthed liar.

7 Dr. Harlow carefully recorded all details of what was perhaps the first in-depth case study of an accidental frontal lobotomy (the destruction of front brain matter). Some of the earliest information on the effects of damage to frontal areas of the brain came from a case study of the accidental injury of Phineas Gage.

8 When a Los Angeles carpenter named Michael Melnick suffered a similar injury, he recovered completely, with no lasting ill effects. Melnick s very different reaction to a similar injury shows why psychologists prefer controlled experiments and often use lab animals for studies of the brain. Case studies lack formal control groups. This, of course, limits the conclusions that can be drawn from clinical observations.

9 Nevertheless, case studies can provide special opportunities to answer interesting questions. For instance, a classic case study in psychology concerns identical quadruplets, known as the Genain sisters. In addition to having identical genes, all four women became schizophrenic before age 25 (Rosenthal & uinn, 1977). The chances of identical quadruplets all becoming schizophrenic are about 1 in 1.5 billion.

10 The Genains, who have been studied for more than 40 years, were in and out of mental hospitals most of their lives. The fact that they share identical genes suggests that mental disorders are influenced by heredity. The fact that some of the sisters are more disturbed than others suggests that environmental conditions also affect mental illness. Myra, the least ill of the four, was the only sister who was able to avoid her father, an alcoholic who terrorized, spied on, and sexually molested the girls. Thus, cases such as this one provide insights that can t be obtained by any other means (Mirsky et al., 2000).

11 Case studies are often conducted in clinical medicine and involve collecting and reporting descriptive information about a particular person or specific environment. They are an important way of illustrating theories and can help show how different aspects of a person's life are related to each other. The method is therefore important for psychologists who adopt a holistic point of view (i.e. humanistic psychologists). The information is mainly biographical and relates to events in the individual's past (i.e. retrospective), as well as to significant events which are currently occurring in his or her everyday life.

12 The Procedure In order to produce a fairly detailed and comprehensive profile of the person, the psychologist may use various types of accessible data, such as medical records, employer's reports, school reports or psychological test results. The interview is also an extremely effective procedure for obtaining information about an individual, and it may be used to collect comments from the person's friends, parents, employer, workmates and others who have a good knowledge of the person, as well as to obtain facts from the person him or herself.

13 Strengths of Case Studies Provides detailed (rich qualitative) information Provides insight for further research Permitting investigation of otherwise impractical (or unethical) situations Case studies give psychological researchers the possibility to investigate cases, which could not possibly be engineered in research laboratories. For example, the Money Case Study.

14 Limitations of Case Studies Can t generalize the results to the wider population Researchers own subjective feeling may influence the case study (researcher bias) Difficult to replicate Time consuming

15 Homework: Log in to the OLI and complete Module 7: Research Designs, pages Complete all of the "checkpoint," "did I get this," "learn by doing," "wrap-up," and other in-course activities. Be prepared to discuss in class. Due 30 Sept: Stranger Paper