Dr. Davis Gates, Associate Director, Schering-Plough Research Institute, is a biostatistician with 10 years of industry experience in the planning and analysis of Phase III clinical trials. Treatment effect sizes of PRO results can at times be difficult to interpret from a clinical perspective, especially when the effect sizes are smaller than the units of the measurement scale. Such effect sizes can be called "fractional-point" outcomes. This presentation will discuss interpretation of results by proposing a basic method to express PRO outcomes in terms of a responder's analysis. In addition, this proposal can be used as a tool to design future clinical trials, which will also be covered. In addition, the presentation will include testing of the proposed method using real clinical trials data.