Question

Please note that for all problems in this course, the standard cut-off (alpha) for a test of significance will be .05, and you always report the exact power unless SPSS output states p=.000 (you’d report p<.001). Also, remember when hand-calculating, always use TWO decimal places so that deductions in grading won’t be due to rounding differences.

Problem Set 2: Chi Square Test of Independence A public opinion poll surveyed a sample of 100 volunteers. Respondents were classified by gender (male or female) and by voting preference (Republican, Democrat, or Independent). Results are shown in the table below. Is there a gender gap – do men’s voting preferences differ significantly from the women’s preferences? Create an SPSS data file to conduct the appropriate statistical test. Rep Dem Ind RT Male 20 18 6 44 Female 28 22 6 56 CT 48 40 12 100

1. Paste appropriate SPSS output. (3 pts)

2. Calculate the effect size (show all work and round to two decimal places) – even if the results were nonsigificant. (1 pts)

3. Paste appropriate SPSS graph. (1 pts)

4. Write an APA-style Results section based on your analysis. All homework “Results sections” should follow the examples provided in the presentations and textbooks. They should include the statistical statement within a complete sentence that mentions the type of test conducted, whether the test was significant, and if relevant, effect size. Don’t forget to include a decision about the null hypothesis. (3 pts)

Answer 1

Answer:

Problem Set 2: Chi Square Test of Independence

A public opinion poll surveyed a sample of 100 volunteers. Respondents were classified by gender (male or female) and by voting preference (Republican, Democrat, or Independent). Results are shown in the table below. Is there a gender gap – do men’s voting preferences differ significantly from the women’s preferences? Create an SPSS data file to conduct the appropriate statistical test.

Ho: there is no association between gender and voting preference

H1: there is an association between gender and voting preference

since data are frequencies, weight command is used.

data:

variables are labled appropriately.

SPSS commands

WEIGHT BY freq.

CROSSTABS
/TABLES=VAR00001 BY VAR00002
/FORMAT=AVALUE TABLES
/STATISTICS=CHISQ
/CELLS=COUNT
/COUNT ROUND CELL
/BARCHART.

1. Paste appropriate SPSS output. (3 pts)

Gender * Voting preference Crosstabulation
Count
		Voting preference			Total
		Rep	Dem	Ind
Gender	Male	20	18	6	44
	Female	28	22	6	56
Total		48	40	12	100

Chi-Square Tests
	Value	df	Asymptotic Significance (2-sided)
Pearson Chi-Square	.298a	2	.862
Likelihood Ratio	.297	2	.862
Linear-by-Linear Association	.289	1	.591
N of Valid Cases	100
a. 0 cells (0.0%) have expected count less than 5. The minimum expected count is 5.28.

2. Calculate the effect size (show all work and round to two decimal places) – even if the results were nonsigificant. (1 pts)

Effect size =sqrt(0.298/100) =0.05458

=0.05 ( rounded)

3. Paste appropriate SPSS graph. (1 pts)

4. Write an APA-style Results section based on your analysis. All homework “Results sections” should follow the examples provided in the presentations and textbooks. They should include the statistical statement within a complete sentence that mentions the type of test conducted, whether the test was significant, and if relevant, effect size. Don’t forget to include a decision about the null hypothesis. (3 pts)

The study was to find is there a gender gap – do men’s voting preferences differ significantly from the women’s preferences. The sample included 100 respondents. Chi square test for association was conducted. The null hypothesis was not rejected and the frequencies were not significantly different, χ² (2, N = 100) = 0.298, p = .862, effect size=0.05.