Semi-empirical determination of the overshooting parameter α_ov as a function stellar mass for the stars in the 33 systems of our sample. Primary and secondary components are plotted together. The size of the points is proportional to Z, the bulk composition (metal-poor stars have smaller symbols). Stars indicated with triangles are those in which the inferred age difference within the binary exceeds our 5% tolerance (see text), but which give otherwise acceptable fits to the observations. Typical error bars for dwarfs and giants are shown on the bottom right.