According to Cohen's conventions for assessing the power of a study, a small effect size is (6) ____________, a medium effect size is (7) ____________, and a large effect size is (8) ____________. Cohen has also expressed the opinion that investigators should plan studies to have a power of (9) ____________. In order to increase the power of their statistical analysis, the psychologists might consider (10) ____________ the size of their sample, using a less (11) ____________ level of significance, or using a (12) ____________ test. However, if the psychologists use a very large sample that results in a small, but (13) ____________ significant, increase in the average number of activities of daily living performed after a treatment like group therapy