Hi Boaz,
I read the K&K paper as primarily a justification for including extremely weak data in refinement (and of course introducing a new single statistic that can judge data *and* model quality comparably). Using CC1/2 to gauge resolution seems like a good option, but I never got from the paper exactly how to do that. The resolution bin where CC1/2=0.5 seems natural, but in my (limited) experience that gives almost the same answer as I/sigI=2 (see also K&K fig 3).
On Dec 7, 2012, at 6:21 AM, Boaz Shaanan <[log in to unmask]> wrote:
> Hi,
>
> I'm sure Kay will have something to say about this but I think the idea of the K & K paper was to introduce new (more objective) standards for deciding on the resolution, so I don't see why another table is needed.
>
> Cheers,
>
>
>
>
> Boaz
>
>
> Boaz Shaanan, Ph.D.
> Dept. of Life Sciences
> Ben-Gurion University of the Negev
> Beer-Sheva 84105
> Israel
>
> E-mail: [log in to unmask]
> Phone: 972-8-647-2220 Skype: boaz.shaanan
> Fax: 972-8-647-2992 or 972-8-646-1710
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> ________________________________________
> From: CCP4 bulletin board [[log in to unmask]] on behalf of Douglas Theobald [[log in to unmask]]
> Sent: Friday, December 07, 2012 1:05 AM
> To: [log in to unmask]
> Subject: [ccp4bb] refining against weak data and Table I stats
>
> Hello all,
>
> I've followed with interest the discussions here about how we should be refining against weak data, e.g. data with I/sigI << 2 (perhaps using all bins that have a "significant" CC1/2 per Karplus and Diederichs 2012). This all makes statistical sense to me, but now I am wondering how I should report data and model stats in Table I.
>
> Here's what I've come up with: report two Table I's. For comparability to legacy structure stats, report a "classic" Table I, where I call the resolution whatever bin I/sigI=2. Use that as my "high res" bin, with high res bin stats reported in parentheses after global stats. Then have another Table (maybe Table I* in supplementary material?) where I report stats for the whole dataset, including the weak data I used in refinement. In both tables report CC1/2 and Rmeas.
>
> This way, I don't redefine the (mostly) conventional usage of "resolution", my Table I can be compared to precedent, I report stats for all the data and for the model against all data, and I take advantage of the information in the weak data during refinement.
>
> Thoughts?
>
> Douglas
>
>
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> Department of Biochemistry
> Brandeis University
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