Before an error localization is to be carried out a preparatory error localization, using only data from an FE-analysis, is justified. The purpose of such preparatory work is both to decide what parameters to use to quantify model errors and to design opti- mal tests for the error localization. A reasonable re- quirement on the parameterization is that the test data are informative with respect to the parameters. That implies that a change of a certain parameter should give a detectable change in the model’s dy- namic behaviour.

The aim of this study is to examine data informa- tivity with respect to physical parameters, used in error localization and model updating. The data in- formativity is here quantified by the use of the Fisher information matrix. It is shown that the in- formativity depends on both excitation and meas- urements. It is reasonable to believe that parameters of which test data have low informativ- ity, are of no use for error localization and should not be used for model updating purposes. Such pa- rameters should be excluded from the parameters set or the test aimed for its determination should be re-designed.