Three college faculty taught large general biology classes using case studies and personal response systems (clickers). Each instructor taught the same eight cases in two different sections, except the questions within the cases differed. In one section the questions were lower order (LO) factual inquiries, and in the other they were largely higher order (HO) application, analysis, or evaluation queries. Using pre- and posttest comparisons on multiple-choice tests and two essay tests, we found that there were striking learning gains using these clicker cases. There were no differences in learning gains between situations when LO questions were used versus HO questions. However, there were distinct differences among different cases, which appear due to the case itself and its topic. The emotional content of the case and its ability to engage students seems partially involved. The most dramatic result in the study was the finding that faculty had great differences in their success using clicker cases which appeared to be more related to their student bodies than teaching styles.