Excerpt 11.24 A Power Analysis Used to
Determine Sample Sizes
The total number of clinical dietitians in the
district directories was 412. From this population, a random sample
of 205 dietitians was selected. The same number of internal medicine
physicians was randomly selected from the physician directory. The
sample size of 205 per occupational group was determined according
to power tables of Kraemer and Theiman. Given an approximate return
rate of 50% per group (i.e., 103 per group), an anticipated small
effect size of .24, and using a two-tailed t-test with a set at
the .05 level, the sample size results in 80% power, which is the
recommended level. Source: M. E. Boxhtari and B. J. Cardinal. (1997).
The role of clinical dietitians as perceived by dietitians and physicians.
Journal of the American Dietetic Association,97(8), p. 851.
Sample Excerpt #2
Excerpt 10.20 Use of the Bonferroni Technique
Independent variables were correlated with liaison
satisfaction. Because 38 correlations were conducted, an a/N correction
was used to reduce the risk of Type I error. To be significant,
a correlation between a variable and liaison satisfaction required
a p-value of .001 or less. Source: L. Bennett and S. Coe. (1998).
Social work field instructor satisfaction with faculty field liaisons.
Journal of Socail Work Education,34(3), p. 374.