STATISTICS 402 - Assignment 5
Due March 15, 2013
1. In a study on memory you analyzed in Assignment 4 the combination of memorization
method and age had statistically significant effects on the average number of words people in
the study could recall. We want to follow up to look more carefully at the effects of these
combinations. You can use JMP to do the subsequent analysis to answer the following
questions.
The JMP data table for the experiment is on the course web site:
www.public.iastate.edu/~wrstephe/stat402.html. Turn in the JMP output and use it to answer
the following questions.
a) Use Tukey’s HSD to compare all possible pairs of treatments. Be sure to report the value
of HSD and indicate which treatment combinations are statistically different.
b) Using the results in a) make comparisons for only the Younger participants. Which
memorization methods are statistically different for Younger participants? Is there a
“best” memorization method for Younger adults? Support your answer statistically.
c) Using the results in a) make comparisons for only the Older participants. Which
memorization methods are statistically different for Older participants? Is there a “best”
memorization method for Older adults? Support your answer statistically.
d) Use a contrast on the treatment means to compare Older participants to Younger
participants. Report the contrast, sum of squares, F statistic and P-value and use the Pvalue to reach a conclusion.
e) Use a contrast on the treatment means to compare the Adjective mean to the Rhyming
mean. Report the contrast, sum of squares, F statistic and P-value and use the P-value to
reach a conclusion.
f) Use a contrast on the memorization method means to compare the Adjective mean to the
Rhyming mean. Report the contrast, sum of squares, F statistic and P-value and use the Pvalue to reach a conclusion.
g) How do the results in e) and f) compare?
2. An alternative to the analysis of the two factors together is to do two separate analyses one
for Older participants and one for Younger participants. Use JMP to do these two separate
analyses.
a) For Older participants, test the hypothesis that there are no differences among the
memorization method means. Be sure to include the F statistic, P-value, decision, reason
for the decision and a conclusion within the context of the problem.
b) Use Tukey’s HSD to determine which memorization methods have statistically
significant differences for Older participants. Be sure to report the value of the HSD.
c) According to this analysis is there a “best” memorization method for Older adults?
Support your answer statistically.
d) For Younger participants, test the hypothesis that there are no differences among the
memorization method means. Be sure to include the F statistic, P-value, decision, reason
for the decision and a conclusion within the context of the problem.
e) Use Tukey’s HSD to determine which memorization methods have statistically
significant differences for Younger participants. Be sure to report the value of the HSD.
f) According to this analysis is ther a “best” memorization method for Younger adults?
Support your answer statistically.
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