SPSS HOMEWORK 7 ASSIGNMENT INSTRUCTIONS
OVERVIEW
This assignment is designed to increase your statistical literacy and proficiency in conducting
and interpreting the chi square test of goodness of fit and the chi square test of independence.
You will be completing one of each type of test in SPSS, using data that are related to specific
research scenarios in the behavioral sciences, such as psychology, social work, and counseling.
Behind the scenes knowledge of how this test is conducted is fundamental to being able to
understand and apply research in your related field to your practice. Additionally, SPSS skills are
professionally valuable, as it is one of the most commonly used statistical software packages in
behavioral science settings, both academic and professional.
INSTRUCTIONS
This assignment includes two problem sets that contain research scenarios and related
questions.
For each scenario, you will run an analysis in SPSS. The required product will include
the SPSS output, an APA-style Results section describing the results, and the appropriate
graph inserted as a Figure in APA style.
For all problems, interpret results based on an alpha level of = .05.
This assignment is worth 60 points.
Please review the two SPSS Homework Tutorials in this module for directions on how to run the
statistical test, as well as the two Results Sections in APA Style presentations, which include a
template for completing an APA-style Results section for the two types of chi square tests. The
scenarios begin on the next page.
Vote to convict
Vote to acquit
Undecided
9
15
6
1. Paste SPSS output. (10 pts)
Problem Set 1: Chi Square Test of Goodness of Fit
Research Scenario: A forensic psychologist is running a jury study to examine factors that
influence jury decisions. He hires actors to conduct a mock trial with the characteristics of
actual criminal trials, with the exception that the “jury” is larger than 12 people in order to
have a larger sample. At the end of the mock trial, he polls the jury participants and asks them
what their decision would be regarding the defendant: vote to convict, vote to acquit, or
undecided. He records the frequencies of answers in the table below.
Using this table, enter the data into a new SPSS data file and run a Chi Square Test of
Goodness of Fit to test whether the proportions are equal across categories. Remember
to weight cases as shown in the presentation. Create a simple bar chart to show the
relationship between the variables. Follow the directions below the table to complete the
homework.
2. Write an APA-style Results section based on your analysis. Include your bar chart as an
APA-style Figure as demonstrated in the APA writing presentation. (Results = 12 pts;
Figure = 8 pts)
Results
As illustrated in Figure 1, most of the jurors decided to acquit and a minority of
the jurors were undecided. A chi-square test of goodness-of-fit was performed to
determine whether the three decisions of the jurors were equally preferred. It was
determined that preference for the three decisions was equally distributed in the
population, X2(2, N = 30) = 4.20, p = .12. Proportions are equal across categories.
Figure 1
Summary of participant’s decisions
Stopped for
pedestrian
Did not
stop for
pedestrian
Standard
Model
20
4
Luxury
Model
9
14
Problem Set 2: Chi Square Test for Independence
Research Scenario: A social psychologist is studying the effects of wealth on driving
behavior. Based on the work of Paul Piff and his colleagues on entitlement and the “empathy
gap” (2012), she positions research assistants and one acting “pedestrian” at a crosswalk in a
state where drivers are required by law to yield to pedestrians in crosswalks as soon as the
pedestrian steps into the crosswalk from the curb. As a car approaches, the pedestrian steps
into the crosswalk, and research assistants record whether the car yields or not. They also
record the type of car as either a more affordable “standard” model or a high-end, expensive
“luxury” model. The results are listed in the table below.
Using this table, enter the data into a new SPSS data file and run a Chi Square Test for
Independence to test whether the price of the car is independent of whether or not the
driver stops for a pedestrian. Remember to weight cases as shown in the presentation.
Create a clustered bar chart to show the relationship between the variables. Follow the
directions below the table to complete the homework.
If you’re interested, check out this article that covers the real experiment that made headlines:
https://wheels.blogs.nytimes.com/2013/08/12/the-rich-drive-differently-a-study-suggests/ as
well as the original article:
Piff, P., Stancato, D.M., Côté, Stéphane, Mendoza-Denton, R., and Keltner, D. (2012). Higher
social class predicts increased unethical behavior. Proceedings of the National Academy of
Sciences, 109(11), 4086-4091.
1. Paste SPSS output. (10 pts)
2. Write an APA-style Results section based on your analysis. Include your clustered bar
chart as an APA-style Figure as demonstrated in the APA writing presentation. (Results =
12 pts; Figure = 8 pts)
Results
A chi-square test of independence examined the relationship between price of car
(Standard model, Luxury model) and whether or not the driver stops for a pedestrian
(Yes, No). The relationship between these variables was statistically significant, χ2(1, N =
47) = 9.71, p < .01. As illustrated in Figure 1, results show that drivers in more expensive
cars are less likely to stop for pedestrians.
Figure 1
Number of drivers who stopped by model type
