Review each of the cases below, and
then in a minimum of 200 words per case, identify the following for each case:
1. Did the case
utilize a randomized or non-randomized experiment? Explain.
2. What design was
used in the study? Please choose from the following list:
·Within
subject designs
·Factorial
designs
·Between
subject designs
·Time
series design
·Interrupted
time series design
·Single
case experimental research design?
3. What threats to internal validity, if any, are present?
Explain.
4. In the example,
was there a third variable problem? If so, define the third variable problem in
the specific case.
5. Did the case use
longitudinal or cross-sectional research?
Case 1: Dr. Watts is
studying the effects of cognitive-behavioral therapy on depression in battered
women. He recruits 100 women for his study from the community by placing an ad
in the local newspaper. The women are randomly assigned to one of two groups;
one group receives treatment with cognitive-behavioral therapy, and the second
group does not receive therapy. Twenty women withdraw from the study before it
has concluded.
Case 2: Mavis is
interested with how children develop play strategies at different points throughout
early childhood development. She designs a research study that looks at 30
children over a period of five years. The children were recruited from a local
daycare where Mavis works. Children were assigned to one of three groups based
on age: Group 1 (age 6 months-12 months), Group 2 (age 12 months 1 day-24
months), and Group 3 (age 24 months-36 months). The children were observed
during recess every six months for a five year period.
Case 3: Dr. Little
designs a research study that looks at the effects of a new antipsychotic
medication on individuals diagnosed with Schizophrenia. He recruits 500
participants for his study from seven local mental health outpatient programs.
He assigns participants to one of two groups: Group A (treated with new medication)
or Group B (treated with an existing medication). Participants are assigned to
one of the groups by randomly selecting a number from a box. Odd numbers were
placed in Group A, and even numbers were placed in Group B.
Case 4: Mary wants to understand how women experience
childbirth. She decides to speak with one woman at a local hospital maternity
unit who has agreed to an interview. Mary uses a semi-structured interview to
gather information from the woman about her delivery experience.
