Written Assignment: Experimental Research

Purpose: To demonstrate and apply your knowledge regarding experimental research methods.

Instructions: There are three parts to this assignment (listed below). For each section, please provide complete answers to all of the questions. Clearly label your answers to each section.

Mechanics: All written work must be typed, double-spaced, and with one-inch margins. Please keep a copy of your report for your own records.

Due Date: This assignment is due at the beginning of class on TBA.  All late reports will be penalized by 10% for each and every day they are late.

Grading Criteria: Your written work will be graded according to the following criteria:

a. Completion of all phases of the assignment.
b. Clear and organized presentation of findings.
c. Accurate application of course concepts.

1. Read the article provided (in class) and answer the questions that follow.

Saragrin, B. J., Rhoads, K. V. L., & Cialdini, R. B. (1998). Deceiver’s distrust: Denigration as a consequence of undiscovered deception. Personality and Social Psychology Bulletin, 24, 1167-1176.

1. Describe the research hypothesis: What does the research hypothesis state?
2. Describe the procedures used to carry out the experiment. What did the typical participant experience?
3. What was the independent variable? How many levels did it consist of? How was each level manipulated or operationalized?
4. Were manipulation checks performed? If so, how?
5. What were the dependent variables? How were they measured?
6. How were participants assigned to experimental groups?
7. Describe the design of this study (one-shot case study, pretest-posted control group, etc.)?
8. What threats to internal validity might be present and how were these threats eliminated (either through design or control)?
9. What statistical tests were used to assess the hypotheses? Describe how the hypothesis was tested.
10. Describe the findings obtained. What did the study find?
11. Based on the methods used and the results obtained, can a causal statement be made? Explain why or why not.
12. What issues might limit the generalizability of these findings?
13. What is your overall impression of this study?

2. A researcher is interested in whether "pro-social" programming which portrays the effects of racial prejudice will affect attitudes towards a minority group. Two groups of 31 subjects each were randomly assigned to one of two conditions. Group A watched a movie, which illustrated the prejudice and hardship that a minority group encounters. Group B watched "Who Wants to Be a Millionaire" for the same amount of that group A watched the move. Both groups were subsequently given a racial attitude test, with lower scores representing a lower level of prejudice. The data are as follows:

            Group A                     Group B
            Mean = 38.62         Mean = 42.60

            The standard error of the difference between the means is 1.36

            Now please answer the following questions:

1. Is this a one-tail or two tail hypothesis?
2. Formulate the appropriate null and research hypotheses.
3. Conduct a t-test
4. State your decision both statistically and in words.