Question

1. State the research hypothesis (non-directional) and the null hypothesis. Make sure you include both DV and IV in the hypotheses from #1 above

2.According to the post-hoc results table, which pairs of the cottages do show the statistically significant difference in “Number of traumas experienced” (e.g. “Cottage A vs. B”)?

SPSS Dataset	SPSS Data for HW (500 cases).sav (available in Canvas)
Variable Names in the dataset	cottage: Cottage assignment (Cottage A, B, & C)
	trauma: Number of traumas experienced

Descriptives
Number of traumas experienced
	N	Mean	Std. Deviation	Std. Error	95% Confidence Interval for Mean		Minimum	Maximum
					Lower Bound	Upper Bound
Cottage A	170	1.88	.902	.069	1.75	2.02	1	4
Cottage B	170	1.59	.494	.038	1.51	1.66	1	2
Cottage C	160	4.75	2.736	.216	4.32	5.18	2	10
Total	500	2.70	2.177	.097	2.51	2.89	1	10

Test of Homogeneity of Variances
Number of traumas experienced
Levene Statistic	df1	df2	Sig.
318.765	2	497	.000

Robust Tests of Equality of Means
Number of traumas experienced
	Statistica	df1	df2	Sig.
Welch	106.654	2	268.787	.000
a. Asymptotically F distributed.

Multiple Comparisons
Dependent Variable:   Number of traumas experienced
	(I) Cottage	(J) Cottage	Mean Difference (I-J)	Std. Error	Sig.	95% Confidence Interval
						Lower Bound	Upper Bound
Bonferroni	Cottage A	Cottage B	.294	.180	.309	-.14	.73
		Cottage C	-2.868*	.183	.000	-3.31	-2.43
	Cottage B	Cottage A	-.294	.180	.309	-.73	.14
		Cottage C	-3.162*	.183	.000	-3.60	-2.72
	Cottage C	Cottage A	2.868*	.183	.000	2.43	3.31
		Cottage B	3.162*	.183	.000	2.72	3.60
Games-Howell	Cottage A	Cottage B	.294*	.079	.001	.11	.48
		Cottage C	-2.868*	.227	.000	-3.40	-2.33
	Cottage B	Cottage A	-.294*	.079	.001	-.48	-.11
		Cottage C	-3.162*	.220	.000	-3.68	-2.64
	Cottage C	Cottage A	2.868*	.227	.000	2.33	3.40
		Cottage B	3.162*	.220	.000	2.64	3.68
*. The mean difference is significant at the 0.05 level.

Answer 1

1.

Null hypothesis:

The mean number of traumas experienced is the same for all three cottages - A, B and C.

Alternative hypothesis(non-directional):

The mean number of traumas experienced is different for atleast one pair from the three cottages - A, B and C.

2.

According to the post-hoc results table, the following pairs of the cottages do show the statistically significant difference in “Number of traumas experienced" :

• Cottage A and C
• Cottage B and C

Conceptual Information

Null hypothesis: Population Parameter of no effect

Directional research hypothesis:

• Directional alternative hypothesis states that the null hypothesis is wrong, and also specifies whether the true value of the parameter is greater than or less than the reference value specified in null hypothesis.
• Non-directional research hypothesis: In this direction of the statement is not specified.

Statistically significant results

We would see the 95% confidence interval and which pairs do not have the value 0 between the lower and the upper limits. If 0 does not lie between the lower and the upper limits, the results are statistically significant.