The determination of stellar characteristics such as the mass, the age or the radius, is crucial when studying stellar evolution, exoplanetary systems or galactic archeology. Thanks to the very high quality data from satellites such as CoRoT, Kepler and now K2, we are able to use seismic modelling to provide very precise values for these quantities. However, these determinations are intrinsically model-dependent and thus the quality of the models used to derive these fundamental properties should be tested. In this talk, we will present how seismic inversions techniques (which have already been used successfully in helioseismology) can be used to test the physical ingredients of stellar models in asteroseismic studies and provide more accurate determinations of the fundamental parameters of asteroseismic targets. We will present the inversion technique we use and its application to the kepler target 16CygA.