Drawn by a vision of solving performance problems in a systematic, systemic and results-based approach, training professionals are turning to human performance technology (HPT). However, many who try to implement HPT find themselves struggling to measure the improvements their interventions are designed to achieve. Ford notes that these difficulties are often due to an attempt to evaluate HPT with models designed solely for training interventions. This article addresses questions of identifying a true root cause, proving that intervention was the causal factor, and calculating return on investment (ROI) of the intervention by (1) Critiquing current evaluation work in HPT and analyzing its shortcomings; and (2) Proposing a new model for HPT evaluation that links the HPT process to the evaluation process, the outputs that clients care most about. Ford concludes by noting that if HPT professionals wish to reap the benefits of HPT, they must be committed to measuring the results of HPT interventions and using that evaluation to both improve the practice of HPT and demonstrate its benefits. (Contains 3 figures.)