Evaluation of method performance involves the consideration of numerous factors that can contribute to error.A variety of measures of performance can be borrowed from the signal detection literature and others are drawn from statistical science.This article demonstrates the principles of performance evaluation by applying multiple measures to osteometric sorting models for paired elements run against data from known individuals.Results indicate that false positive rates are close,on average,to expected values.As assemblage size grows,the false positive rate becomes unimportant and the false negative rate becomes significant.Size disparity among the commingled individuals plays a significant role in method performance,showing that case-specific circumstances (e.g.assemblage size and size disparity) will determine method power.