statistics homework

Research Methods in Psychology

Assignment 5

1. Conduct a multiple (linear) regression analysis on your group’s survey data using SPSS; the predictors that you put into your model should be the ones you initially thought would be successful. If you’re not sure how to do the regression, you may want to consult Chapter 12 of “A Crash Course in SPSS.” Then do the following:

a) Print out and turn in a copy of the summary results. 2 pts.

b) What was the outcome (response) variable in your regression model? What variables did you put into the regression as possible predictors? Be specific – write out the questions if necessary; it needs to be clear to me what they were. 3 pts.

c) What variable(s) were significant predictors, according to the regression analysis? 3 pts.

d) Using the standardized regression coefficients, which variable had the largest effect (or was most important)? 1 pt.

e) Interpret the unstandardized coefficient of the variable identified in (d) in terms of your predictor (independent) and outcome (dependent) variable. That is, explain how the outcome variable moves as the predictor in (d) moves. 1 pt.

f) How much variance was accounted for by your regression model? According to your regression output, there is still some variance in your outcome variable (DV) that is left unexplained. That means your R2 is less than 100%. If you were to do this again (i.e., edit your survey and collect new data), what other predictors would you add? Discuss 2 new questions and describe how they would relate to (i.e., correlate with) your current outcome variable. 3 pts.

2. Analyze the demographic data that you collected in your survey. You will need to use SPSS to calculate frequencies, means, etc (whatever’s appropriate). Then create a table like the one below to describe your sample (i.e., survey respondents). Create your table using Microsoft Word or some other word processing program; to make it look nice, you will need to use tabs. Make your table descriptive, accurate, easy-to-read, and aesthetically pleasing (pretty); your score will depend on it.

5 pts.

Table 1. Respondent Characteristics (n=249)

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Characteristic

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Sex (% men) 98

Mean age in years 46

Mean years in health profession 13

Religious affiliation (%)

None 13

Jewish 13

Catholic 22

Protestant 43

Other 10

Signed organ donor document (% yes) 87

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Read Chapter 12 from Seeing Statistics. Then answer the questions below.

3. Answer “Discovery” questions 1 and 2 in Chapter 12.5.1 (Interpreting the Line). 1 pt.

4. Click on “Applications” in Chapter 12.5.1 (Interpreting the Line). Answer the 2 questions posed for the Biology (low-cholesterol diet) example. 1 pt.