Major corporations are emphasizing the importance of evaluating marketing and public relations functions more and more these days. However, while companies do report using various evaluation tools, they do not report the findings of their evaluation studies quite so often. Furthermore, evaluations of special events like open houses are all too often limited to the subjective assessments of a few key senior managers. This article reports on an evaluation of an open house using research methods, which produce a more objective and therefore more accurate measure of the special event. Since the article is intended to be a model for others to follow, the methods used to conduct the evaluation are explained. The article describes (1) how many and who attended the open house at Kaiser Permanente's Park Sierra Medical Offices in Riverside, California (employees, current Health Plan members and prospective enrollees); (2) what the attendees' perceptions were of the event and the company organizing it; (3) whether or not they learned anything at the open house; and more.