This article provides recommendations from the National Multiple Sclerosis Society's Clinical Outcomes Assessment Task Force. The Task Force was appointed in 1994 and charged with recommendending improved approaches for clinical outcomes assessment in future controlled clinical trials. The recommendations herein follow extensive deliberation and data analysis during 2.5 years. General principles and desirable measurement attributes were used to assess alternative measurement techniques and clinical scales. On the basis of the analysis of existing multiple sclerosis (MS) data sets, a new measurement approach is proposed. The approach is based on quantitative functional composites that consist of simple quantitative measures from the major clinical dimensions of MS combined into a single score. Quantitative functional composites are likely to provide improved precision and sensitivity in future MS clinical trials. Studies necessary to further refine quantitative functional composites as useful MS clinical trial outcomes are delineated.