Describe the different ways of establishing variation in an independent variable.
PY 354-Introduction to Psychological Research
Winter, 2014
This exam will evaluate how well you understand the material in the class so far. It covers the information presented in Chapters 1-4 of the McBride text, as well as the course notes that I have provided. You may use your book, notes, or outside resources to help you with your exam, but you may NOT consult with each other. Also, do not simply copy/paste information from any source…put things into your own words and use your own examples!!! Evidence of copy/paste or other forms of plagiarism will result in a score of 0 for the exam. If you use an outside source, cite it properly and provide an APA style reference list at the end of your exam. (100 points)
Part A: Research Scenarios—Read each scenario carefully. At times, I may ask for a definite answer and at other times, a potential answer. Each scenario is worth 10 points.
A researcher wants to examine the effects of LSD on complex learning in rats. One group of rats was given a very small dose that would be unlikely to cause any behavioral effects. The second group of rats was given a larger dose of the drug. Both groups of rats then ran through a complex maze several times.
a. What is the independent variable (s) and is it a true or subject variable:
b. What is the dependent variable(s):
c. Name some of the possible control variables:
d. What would you have done differently?
A social psychologist is interested in helping behavior. This researcher is particularly interested in how group size affects whether or not an individual will help someone else in the group. A study was conducted to assess the question.
a. What would be the IV(s) and would it be a true or subject variable:
b. What would be the DV(s):
c. Name some possible control variables:
d. How would you conduct this study?
Doctor Daze has just completed an experiment on the influence of gender and exposure to violent television on the aggressiveness of preschool age children. He had the children watch either a violent or a non-violent cartoon. He then recorded the number of aggressive encounters the children engaged in in a 30 minute period.
a. Independent variable(s) and type (true or subject):
b. Dependent variable(s):
c. Possible control variables:
d. What would you do differently:
A statistics teacher wanted to compare two methods of teaching introductory
statistics. One method relied heavily on teaching the theory behind statistics (theory method). The other method consisted of teaching the student various statistical tests and explaining when to use each test (the cookbook method). The teacher found that a leading engineering school was using the theory method in all of its introductory statistics classes and that a state teachers college was using the cookbook method in all of its classes. At the end of the semester, the teacher administered a standardized statistics test to both sets of classes. The results indicated that the classes that received the theory method performed better than did the classes that received the cookbook method. The teacher concluded that the theory method was the superior method and that it should be adopted by statistics teachers.
a. Independent variable(s) and type (true or subject):
b. Dependent variable(s):
- Possible control variables:
- What would you do differently:
Part II: Read the summary of the research article that appears on the
next page of the exam and answer the following questions: (30 pts.)
a. What is the independent variable(s) and its levels? Is it a true or subject variable?
b. What is the dependent variable(s)?
c. What type of control variables were or could be used?
d. What type of research procedure (method) was used (e.g., experiment, survey, etc.)
e. What was the hypothesis being tested?
f. Did the results support the hypothesis?
g. Do you think this was a good study? Explain your answer.
Research example: Anorexia Nervosa
Clinton, D. N., & McKinley, W. W. (1986). Attitudes to food, eating, and weight in
acutely ill and recovered anorectics. British Journal of Clinical Psychology, 25,
61-67.
Article summary: Anorexia nervosa is a condition characterized by chronic failure to eat for fear of gaining weight. The chief symptom is extreme loss of weight brought on by refusing food or by eating and then ejecting food through (self-induced) vomiting or consumption of laxatives. Other symptoms include periods of overactivity and distorted attitudes toward food and eating. The anorexic is typically female and between the ages of 12 and 18 at time of onset. Severe cases of anorexia nervosa, unless treated, may result in death.
The authors of the present study suggested that although clinical intervention may result in improved weight gain among acutely ill anorexics, nevertheless, the “recovered” anorexic is likely to continue to show evidence of “distorted attitudes to food, eating, and weight.” To test this idea the investigators administered the Eating Attitudes Test (EAT) to four groups of females: acutely ill anorexics (n=15), recovered anorexics (n=14), psychiatric controls (n=10), and normals (n=24). Both the acutely ill and recovered anorexics were shown to be similar at time of onset, although the recovered group had been slightly younger (15.7 years) at the time of onset than the currently ill group (17.3 years). For example, the average weight loss (in terms of percentage of matched population mean weight) was 31.1 percent for the acutely ill and had been 34.4 percent for the recovered group. To obtain the recovered sample, 26 former patients meeting the study’s selection criteria were contacted; 6 could not be located, 2 refused to participate, and 4 failed to make appointments, resulting in 14 recovered individuals who received the EAT. Mean length of time since discharge for the recovered group was 42.6 months. The psychiatric controls were patients hospitalized for a variety of disorders, including schizophrenia and depression, but who showed no evidence of eating disorder. The normals were nursing students who showed no evidence of eating disorder or other psychiatric disturbance based on responses to a brief questionnaire designed by the authors. The mean ages of the four groups were not significantly different based on a between-subjects ANOVA.
The EAT is intended to measure both behavioral (e.g., vomiting, dieting) and attitudinal aspects of anorexia nervosa. Subjects responded to 40 statements using a 6-point scale ranging from “very often” to “never”. Mean scores (and standard deviations) for the four groups (higher numbers indicated more extreme responses) were: anorexics 51.5 (30.7); recovered anorexics 31.8 (28.8); psychiatric controls, 13.6 (10.05); and normals, 7.9 (4.7). The results of a one-way ANOVA were statistically significant. A post-hoc test (Scheffe) revealed that the acutely ill females had statistically higher EAT scores than did the psychiatric females or the normal females. The EAT scores of the currently ill and recovered subjects were not significantly different, although the recovered group had significantly higher scores than did the normals. The authors concluded that the present treatments for anorexia nervosa, although successful in treating gross physical and behavioral symptoms, leave the distorted attitudes associated with this condition relatively unaltered. Important questions for future research are whether these attitudes serve to slow down treatment, contribute to relapse rates, or are distressing in themselves to the individuals.
Part C: Short answer essays—Answer any three (3) of the following questions. (10 points each).
1. Describe the steps involved in the scientific method.
2. Describe the different ways of gaining knowledge about the world.
3. Describe the characteristics of the scientific approach.
4. List and describe the different types of validity.
5. Describe the different ways of establishing variation in an independent variable.
6. List the different types of dependent variables.
7. Outline the important influences, events, and figures in the history of experimental psychology.