SOCI 332 Week 5 exercise question 7

Siegel (1990) found that elderly people who owned dogs were less likely to pay visits to their doctors after upsetting events than were those who did not own pets. Similarly, consider the following hypothetical data. A sample of elderly dog owners is compared to a similar group (in terms of age and health) who do not own dogs. The researcher records the number of visits to the doctor during the past year for each person. The data are:
Non-dog owners: 10, 8, 7, 9, 13, 7, 7, 12
Dog owners: 7, 4, 9, 3, 7
Assume that number of doctor visits are normally distributed in the population.

A) Is the number of doctor visits significantly different for dog owners than for non-dog owners? Note that tcrit is 2.20 for an alpha of .05 for these df.

SS1 = 38.9
SS2 = 24

sp^2 = (38.9 + 24)/(7 + 4) = 5.71

t(11) = (9.125 – 6)/sqrt(5.71/8 + 5.71/5) = 2.29, p < .05


B) Provide a proper effect size estimate and provide an interpretation of it in a single sentence.

Cohen’s d = 3.125/sqrt(5.71) = 1.31. The mean number of doctor visits for non-dog owners is 1.31 standard deviation units above the mean number of dog owners.

C) Provide a 95% confidence interval for these findings.

CI = 3.125-2.2*1.36, 3.125+2.2*1.36 = [.128,6.12]

D) What, in words, does your confidence interval above mean?

This is the interval in which the true mean of the population lies with 95% confidence.

Thank you so much!

Post Merge: 9 years ago

Would this exercise  work with this control group and dog owners? Please let me know.
Thank you.

Control Group   Dog Owners
12   8
10   5
6   9
9   4
15   6
12   
14