An international assessment is currently being conducted comparing the outcomes predicted by a diverse set of HRA methods against the observed performances of licensed operator crews in simulated accident scenarios at the HAMMLAB (HAlden huMan-Machine LABoratory) simulators at the Halden Reactor Project. This paper addresses the methodology for the comparison including how the HRA analyses results and the performance of the operator crews in the simulated scenarios were represented to allow the comparison. In regards to the HRA analyses, steps were taken to address the challenge created by the differences in scope and terminology used among the methods including: a) asking the HRA teams to use a common taxonomy to list the driving performance shaping factors in addition to a response in terminology proper to the method and b) to discuss the "operational expression" of the driving factors. The paper will discuss how these elements of the HRA teams' responses were subsequently integrated by the evaluation/assessment group into a summary set of predictions that could be compared to the results from the operating crews in the simulator. On the simulator data side, the comparison begins with the broad set of observations and measures used during the simulator sessions and during debriefing. To enable the comparison, this data must be reduced to a set of outcomes that represent the overall performance of all crews in the scenarios.