1. (Rubin 1975), the inclusion of residuals appears as accurate as or even more accurate than restrained modal approaches. For components from test, the residual flexib i l i t y approach i s particularly appealing because the free-free modal testing can be used. Free-free modal testing with the inclusion of residual flexibility has been proven to be feasible (Klosterman 1972). The limitation of the residual flexibility i n defining a flexible component t o be rigidly connected i s not known. If the stiffness of a very localized structural region near a connection i s important i n response of the component and i n component loads, the constrainedmode approaches are likely t o be more accurate.