At the University of Washington, we have been developing a suturing simulator using novel finite element model techniques which allow real-time haptic feedback. The issues involved in measuring validity in a suturing model have not been examined in a systematic way. Very few studies exist on the surgical factors that lead to good sutures. We have examined published data on these factors as well as previously studied metrics in suture training. This information has been combined with a review of types of validity (e.g., face, construct, predictive and concurrent) and reliability that must be considered in assessing any surgical simulator.