Training interventions can be evaluated by calculating return on investment (ROI) and cost-benefit analysis. The four-level model proposed by Kirkpatrick is the dominant evaluation model used. Calculating ROI has been a critical issue for trainers and executives, but only a few organizations have implemented the process that is considered as difficult, impractical, and expensive. Since organizations have moved from training for activity to training for impact, determining ROI is a key process to measure training accountability. Strengths of ROI are that organizations connected training with strategic goals, used a variety of methods to collect data and implemented attempts to isolate training effects, defined units of measurement, calculated monetary value of improvements, and gathered measurements before and after training. These successful practices have stated accountability for participants, managers, and HRD staff. Challenges are that each organization applies different methods to determine costs; practitioners are not implementing appropriate methods to isolate the influence of training on organizational goals; and results from HRD programs are not converted into monetary values. Major conclusions are that ROI implementation has relevant benefits for organizations; isolation and value of money over time are two important elements that should be considered; and HRD practitioners would benefit from applying principles of research design to evaluation processes. (31 references) (YLB)