[en] The U.S. LMFBR programs have sponsored a number of intercorrelation experiments which seek to provide a basis for predicting neutron-induced property changes from a large variety of charged particle simulation data. The results of these and other programs are reviewed and lead to the conclusion that simulation experiments are quite valuable in meeting the goal of providing guidance for design of fission or fusion energy generation devices. Numerous examples are given of simulation experiments which have been influenced or dominated by the presence of unrecognized atypical variables. All major U.S. intercorrelation activities have been concerned primarily with void growth experiments to simulate fast reactor conditions. This reflects not only the early program emphasis on this important radiation-induced phenomenon but also the fact that void swelling is the only high fluence property change which leaves a cumulative microstructural record in the small material volumes characteristic of simulation experiments. Based on past experiences, guidance is provided for application of intercorrelation results to environments other than those found in fast breeder reactors, and to property changes other than swelling