Case Studies
RESEARCH METHODS
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)
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).
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.

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.
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.
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.

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.

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.

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).

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.
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.
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.
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
Homework:

Log in to the OLI and complete Module 7: Research Designs, pages
39-41. 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