Question

SPSS Module 5 Assignment—Independent t Test

General Instructions:   In this assignment, we will be examining 2 Independent t tests and interpreting the results. As with previous assignments, the Aspelmeier and Pierce texts does a wonderful job of explaining how to actually run the tests in Chapter 7. Follow their instructions for interpretation of these test as you complete this assignment. Once again I have run the test and given you the SPSS output you will need to complete this assignment.

Independent t test:

The researchers want to compare older females to younger females on their ratings of Loyalty. Also, researchers want to compare Freshman and Sophomores on their reported number of friends. As we learned from the text and the PPTs, we know these research situations require the use of the Independent t Tests. Here are the researchers’ hypotheses:

The researchers think that older females will report more loyalty with their closest female friend than will younger females.

The researchers also believe that Freshmen will report having more friends that Sophomores.

Part 1—The Analyses

For this assignment, I’ve run 2 Independent t Tests: one comparing older and younger females on loyalty and one comparing Freshmen and Sophomores on number of friends.

Output:

Hypothesis One Independent T-Test

Group Statistics
	agegrp	N	Mean	Std. Deviation	Std. Error Mean
Loyalty	1.00	47	59.62	7.070	1.031
	2.00	53	61.38	4.486	.616

Independent Samples Test
		Levene's Test for Equality of Variances		t-test for Equality of Means
		F	Sig.	t	df	Sig. (2-tailed)	Mean Difference	Std. Error Difference	95% Confidence Interval of the Difference
									Lower	Upper
Loyalty	Equal variances assumed	3.504	.064	-1.504	98	.136	-1.760	1.171	-4.083	.563
	Equal variances not assumed			-1.465	76.128	.147	-1.760	1.201	-4.153	.632

Hypothesis Two Independent T-Test

	Group Statistics
				Year in College				N		Mean			Std. Deviation		Std. Error Mean
	Number of Female Friends			Freshman				59		5.42			3.024		.394
				Sophomore				41		5.10			2.836		.443
Independent Samples Test
			Levene's Test for Equality of Variances			t-test for Equality of Means
			F		Sig.	t	df		Sig. (2-tailed)		Mean Difference	Std. Error Difference		95% Confidence Interval of the Difference
														Lower		Upper
Number of Female Friends		Equal variances assumed	.031		.860	.544	98		.588		.326	.600		-.864		1.516
		Equal variances not assumed				.550	89.612		.583		.326	.593		-.851		1.503

Part 2—The APA Write-Up Instructions

               As with previous assignments, the American Psychological Association (APA) has standards for how statistical results should be presented. While the actual word choice varies, there are several essential components that are common among all presentations of statistical results and interpretations. Use the following instructions for ALL APA write-ups required for this course:

For each analysis, use the following steps to write a complete description of results in proper APA format.

State what hypothesis was tested.

State what test was used.

What decision did you make? Reject the null or retain (fail to reject) the null.

Were the groups significantly different from each other?

Report the means and standard deviations for each group.

Put numbers in APA format:

General Format: symbol for the test (df)= obtained value, p> or < significance level

Specific for t Tests: t(99)=1.98, p<.05

After this you need to put either equal variances assumed OR equal variances not assumed depending on the results of the Levene’s Test

Report Effect Size (if known)

Example:

        Adolescent males were expected to score significantly higher on a measure of aggression than were adolescent females. An independent t test was used to test the hypothesis leading to the rejection of the null hypothesis. Adolescent males (M=14.67, SD=2.35) were significantly more aggressive than were adolescent females (M=9.65, SD=1.59), t(78)=3.93, p<.05, equal variance assumed.

Since we ran 2 analyses, you will do 2 write-ups for this assignment. Remember to use chapter 7

Hypothesis One: The researchers think that older females will report more loyalty with their closest female friend that will younger females.

Answer the following questions

What is the null hypothesis tested?__________________________

Can we assume equal variances? (Was the Levene’s Test for Equality of Variance significant or not significant?)

Write up the results for the Independent t Test for Hypothesis One below:

Hypothesis Two: The researchers also believe that Freshmen will report having more friends that Sophomores.

Answer the following questions

What is the null hypothesis tested?__________________________

Can we assume equal variances? (Was the Levene’s Test for Equality of Variance significant or not significant?)

Write up the results for the Independent t Test for Hypothesis Two below:

Answer 1

1. a. H0: mu_old-mu_young<=0 (mean loyality scores for older females towards female friends is atmost same that of younger females).

b. The Levene's test is not significant at alpha=0.05 level (p=0.064), therefore, one cannot assume equal variances.

c. Older females were supposed to score higher in terms of loyality towards female friends than their younger counterparts. An independnet t test is used to test the hypothesis, leading to failure of rejection of null hypothesis. There were insufficient sample evidence to cocnclude that older females (M=59.62, SD=7.07) show significantly higher loyality towards female friends compared to their younger counterparts (M=61.38, SD=4.486), p value not less than 0.05, equal variance not assumed.

2.

1. a) H0: mu_freshman-mu_sophomores>0 (mean number of friends is higher for freshman)

b) Levene's test is not significant, p not less than 0.05.

c) Freshman were supposed to have morefriends than sophomores. An independnet t test is performed leading to non rejection of null hypothesis. There is insufficient sample evidence to conclude that the freshman (M=5.42, SD=3.024) has more number friends than sophomores (M=5.10, SD=2.836), p value not less than 0.05, equal variance not assumed.