Written by a social worker for social work students, this is a nuts and bolts guide to statistics that presents complex calculations and concepts in clear, easy-to-understand language. It includes numerous examples, data sets, and issues that students will encounter in social work practice. The first section introduces basic concepts and terms to…

A concise table is presented based on a general measure of magnitude of effect which allows direct determinations of statistical power over a practical range of values and alpha levels. The table also facilitates the setting of the research sample size needed to provide a given degree of power. (Author/CM)

When reporting results, researchers must not change predetermined significance levels. Such attempts to make results more significant are statistically inaccurate, illogical, and unethical. American Psychological Association standards for reporting significance should be more explicit. (CP)

In two treatment-repeated measurements designs, the ratio between the unbiased variance of the differences and twice the variance of the errors of measurement can be used to test for interaction of subjects and treatments. The use of this statistic is illustrated. (Author/CP)