Question

Problem Set 2: The Two-factor ANOVA for Independent Measures

Research Scenario: In response to media reports of violence on college campuses, a psychologist who works at a local community college decides to study students’ perceptions of campus safety. He hopes to use these results to help develop an on-campus violence prevention program. The administration has asked him additionally to look at whether perceptions of safety differ depending on students’ year in school and gender. The psychologist administers a questionnaire with possible scores ranging from 1-70, with higher scores indicating higher perceptions of safety on campus, and lower scores indicating perceptions that the campus is less safe. Based on the data collected below, do year in school and/or gender have an effect on perceptions of campus safety?

Using this table, enter the data into a new SPSS data file and run a two-way ANOVA to test whether there is a difference in patients’ depression scores among the three therapists. Create a multiple line graph to show the difference among these scores.

Male	Freshmen	Sophomore	Junior	Senior
	39 66 54 66 60	44 32 62 59 29	63 67 46 51 41	45 53 68 57 60
Female	51 46 45 57 32	32 21 30 49 53	56 52 60 47 59	61 55 42 58 61

1. Paste SPSS output.  

2. Write an APA-style Results section based on your analysis. Include your line graph as an APA-style figure as demonstrated in the APA writing presentation. Please write out this section just as a scientific results section, please! It is very important....thank you!

Answer 1

ANSWER:

Given that,

Descriptive Statistics
Dependent Variable:   Score
Gender	Year	Mean	Std. Deviation	N
Male	Freshmen	57.00	11.225	5
	sophomore	45.20	15.090	5
	Junior	53.60	11.082	5
	senior	56.60	8.503	5
	Total	53.10	11.801	20
Female	Freshmen	46.20	9.257	5
	sophomore	37.00	13.509	5
	Junior	54.80	5.357	5
	senior	55.40	7.893	5
	Total	48.35	11.609	20
Total	Freshmen	51.60	11.247	10
	sophomore	41.10	14.177	10
	Junior	54.20	8.230	10
	senior	56.00	7.760	10
	Total	50.73	11.802	40

Tests of Between-Subjects Effects
Dependent Variable:   Score
Source	Type III Sum of Squares	df	Mean Square	F	Sig.
Corrected Model	1799.975a	7	257.139	2.266	.054
Intercept	102921.025	1	102921.025	906.793	.000
Gender	225.625	1	225.625	1.988	.168
Year	1333.075	3	444.358	3.915	.017
Gender * Year	241.275	3	80.425	.709	.554
Error	3632.000	32	113.500
Total	108353.000	40
Corrected Total	5431.975	39
a. R Squared = .331 (Adjusted R Squared = .185)

Result:

A two-way analysis of variance yielded a main effect for the gender, F(1, 32) = 1.99, p=.168, such that the average score was not significant. The main effect of year was significant, F(3,32) = 3.92, p=.017. However, the interaction effect was not significant, F(3,32) = 0.71, p = .55.