[en] An attempt to verify the reliability of the experimental modal modeling code, MODAL-PLUS, is described in this report. MODAL-PLUS is capable of synthesizing a modal model of a structure using data from dynamic testing of a structue. The objective was to determine whether a modal model synthesized from one set of test data would be capable of correctly predicting response to a different form of excitation from a different set of data. Recorded test data from the shaker and rocket tests on the containment building of the HDR (Heissdampfreaktor) were used in the effort. The attempted verification was only partially successful in that only one modal model with a limited range of validity could be synthesized from the shaker test data. The goodness of fit in this limited range was adequate. The rocket test data could not be used to synthesize a modal model due to numerical difficulties. However, the effort was useful in showing the need for taking into account the possible use of the data, and the data analysis method to be employed, at an early stage when the tests are being designed