The consequences of using three different interpolation methods for tabular neutron and photon energy distribution data are investigated. The three methods are linear interpolation on energy, linear interpolation on energy after the secondary energy ranges are transformed to unit base, and linear interpolation on energy after the initial distributions are converted to cumulative probability distributions by integration over the secondary neutron or photon energy. The latter two methods may subsequently be reconverted to differential probabilities. Linear interpolation on energy without transformation or conversion is shown to be the least desirable for most applications.