This paper summarizes two basic ROI measurement methodologies using case studies from companies that have implemented measurable sales incentive programs in the past, and offers insights into understanding the data requirements relative to these two methodologies. It explains that Post-Hoc Measurement is essentially the use of field experimentation using historical data, while Outcome-Based Measures considers such areas as accounts receivable and inventory levels that can be affected by sales improvements. Published by: Incentive Research Foundation