May 31, 2007
by Ryan Sasaki, NMR Product Manager, ACD/Labs
Peter Murray-Rust and Tony Williams have added their two cents to this debate on their respective blogs.
Peter provides a great justification on providing open access to scientific information:
In the case of NMRShiftDB I am firmly of the opinion that it leads the way in opening access to scientific information. If the community wishes it can use it as a growing point to develop more and better data. If they don’t, they will continue to use existing non-open systems (or in most cases not use anything at all).
Tony goes into more depth about the details of the ACD/Labs validation study and specifically addresses Wolfgang’s claim on large error:
What I do NOT mean is that a chemical shift at 120ppm is predicted to be at 80ppm and therefore there is a large error. No, the chemical shift at 120ppm could be experimentally correct but the prediction algorithm could fail to predict it correctly.
What I DO mean is that an assignment of a particular nucleus to 120ppm may be entered into the database but the ACTUAL shift should be 12ppm….that additional zero just showing up as an error during the submission process. So, the errors I am pointing to are those of incorrectly drawn structures, mis-assignments, transcription errors and other potential sources of error. My estimates refer to the number of significant assignment or structural errors that were glaringly incorrect and I was subjectively thinking of situations where the difference between the actual experimental shift value and the one assigned to nucleus was >20ppm….this does not mean that mis-assignments of even 1ppm are any less importance, just not necessarily as easy to detect and not part of my subjective criteria.
At present, the data have been examined in more detail and I believe I overestimated…a report of potential glaring errors has been returned to Christoph for him to examine and make changes to the database as he sees fit. Glaring errors are less than 250 in number based on my subjective criteria. Again, this does not mean that there aren’t hundreds or thousands of errors buried in the data…they are not obvious errors and require more manual examination.
Make sure you check out their blogs.
EDIT: This conversation has continued in the following entries (in order):
http://acdlabs.typepad.com/my_weblog/2007/06/robiens_and_mod.html
http://acdlabs.typepad.com/my_weblog/2007/06/note-from-an-nm.html
http://acdlabs.typepad.com/my_weblog/2007/06/the_purgatory_d.html