The selection of a single method of analysis is problematic when the data c
ould have been generated by one of several possible models. We examine the
properties of two tests designed to have high power over a range of models.
The first one, the maximum efficiency robust test (MERT), uses the linear
combination of the optimal statistics for each model that maximizes the min
imum efficiency. The second procedure, called the MX, uses the maximum of t
he optimal statistics. Both approaches yield efficiency robust procedures f
or survival analysis and ordinal categorical data. Guidelines for choosing
between them are provided.