Question

Application Exercise:
A team of comparative psychologists are interested in the maternal behavior or rats. In an experiment, 5, 20, and 30 day-old rat pups were separated from their mothers. They then recorded the time (in seconds) required for the mother rats to retrieve the pups. The psychologists were interest in whether retrieval time varies with age. The data are given below. What can be concluded with α = 0.05?

5 Days Old	20 Days Old	30 Days Old
16 11 26 16 21 19	31 16 21 26 24 23	31 26 41 23 36 31

a) What is the appropriate test statistic?
---Select---na, one-way ANOVA, within-subjects ANOVA, two-way ANOVA

b) Obtain/compute the appropriate values to make a decision about H₀.
critical value = _____________; test statistic =__________
Decision: ---Select---Reject H0, Fail to reject H0

c) Compute the corresponding effect size(s) and indicate magnitude(s).
η² = ; ---Select---na, trivial effect, small effect, medium effect, large effect

d) Make an interpretation based on the results.

-At least one of the rat pup ages differed on the mother retrieval time.

-None of the rat pup ages differed on the mother retrieval time.    

e) Regardless of the H₀ decision in b), conduct Tukey's post hoc test for the following comparisons:
1 vs. 2: difference = __________; significant: ---Select---Yes or No
2 vs. 3: difference =__________ ; significant: ---Select---Yes or No

f) Regardless of the H₀ decision in b), conduct Scheffe's post hoc test for the following comparisons:
1 vs. 2: test statistic = _________; significant: ---Select---Yes or No
2 vs. 3: test statistic = _________ ; significant: ---Select---Yes or No

Answer 1

a) What is the appropriate test statistic?
one-way ANOVA
b) Obtain/compute the appropriate values to make a decision about H₀.
critical value = 3.682; test statistic = 8.405
Decision: Reject H0

c) Compute the corresponding effect size(s) and indicate magnitude(s).
η² = 0.528; medium effect

d) Make an interpretation based on the results.

-At least one of the rat pup ages differed on the mother retrieval time.

e) Regardless of the H₀ decision in b), conduct Tukey's post hoc test for the following comparisons:
1 vs. 2: difference = -5.3333; significant: No
2 vs. 3: difference = -7.83333 ; significant: -No

f) Regardless of the H₀ decision in b), conduct Scheffe's post hoc test for the following comparisons:
1 vs. 2: test statistic = -1.651; significant: No
2 vs. 3: test statistic = -2.425 ; significant: No