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On Tuesday, December 06, 2011 09:13:03 am Jacob Keller wrote: > Dear Crystallographers, > > I hate to broach this subject again due to its wildly controversial > nature, but I was wondering whether there was any reference which > systematically analyses resolution cutoffs as a function of I/sig, > Rmerge, Rmeas, Rpim, etc. I strongly dislike Rmerge/Rcryst for > determining cutoffs, for obvious reasons--and especially for datasets > of higher multiplicity--but nevertheless it is a ubiquitously-reported > statistic, and one therefore has to make an argument against using it. What is your question, exactly? I don't follow the logic that because a statistic is reported, one must therefore argue against it. > Hopefully this could be done by pointing to a definitive reference--or > am I stuck with a convention versus the truth? Maybe the ACA or > similar could make a public anti-Rmerge proclamation about it, to make > it easier for us? Acta published at one point a guideline as part of the instructions to authors, but the state of the art passed it by very soon after. I suspect that is the inevitable fate of any such broad-brush proclamation. Ethan > > Also, more generally, it seems that the refinement programs are now > better able to discount lousy high-res data, so why not leave the > choice to those programs, and just give them all of the data to the > edge of the detector, especially since our computational and data > storage capacities are now completely sufficient for that? One could > then use some other metric for the goodness of the structure, such as > what bin crosses the Rfree = 40% mark or something. > > One could push this even further and, as has been mentioned on this > list before, just give the refinement program all of the intensities > of the voxels in the 3D dataset? > > Jacob > > -- Ethan A Merritt Biomolecular Structure Center, K-428 Health Sciences Bldg University of Washington, Seattle 98195-7742