Hi Stefano, Check out this paper: H. J. Krappe and H. H. Rossner, Phys. Rev. B 61, 6595 (2000). The authors use a Bayesian analysis, and if I recall correctly, they determine that the amount of actual information present is considerably less than that given by the commonly used Nyquist criterion. That's because the Nyquist criterion assumes "ideally packed" information, as if EXAFS was a designed radio signal. Of course, the EXAFS gods had no particular reason to send us information in that form, so the information content is somewhat lower. To me, that makes the debate between +0, +1, and +2 somewhat moot...lacking a better method, I generally figure I should avoid having Nvar more than about 2/3 of Nidp, which is certainly satisfied in your case. Personally, I use the +0 formula when reporting the number of independent points, since it is the most conservative of the commonly used choices. --Scott Calvin Sarah Lawrence College