  We explore the feasibility of applying the Christensen-Dalsgaard diagram to
real asteroseismic data and provide quantitative measures of the uncertainty
associated with the results. We also propose a new kind of seismic diagram,
based on the determination of the locations of sharp acoustic features inside a
star. We show that by combining the information about the position of the base
of the convective envelope or the HeII ionisation zone with a measure of the
average large separation, it is possible to constrain the unknown chemical
composition or the various parameters characterising the physical processes in
the stellar interior. We demonstrate the application of this technique to the
analysis of mock data for a CoRoT target star.
