Starting this January, I observe more and more inconsistencies in the MathSciNet citation database. A typical situation is that the number of citations shown in the description of a paper differs from the number of matches that one actually gets by following the link. For example, take papers by Gerd Faltings (sorted by the number of citations). MR0718935 is listed with 347 citations, but has only 340 matches; MR1083353 is listed with 304 citations, but has only 303 matches; MR1463696 is listed with 133 citations, but has only 129 matches, and so on. Moreover, the number of matches depends on the mirror. The above numbers are provided by the Providence cite. The Bielefeld mirror gives, respectively, 340 (the same number), 302 (one less) and 131 (two more). Is there any good explanation for this phenomenon? 



Inconsistencies in MathSciNet citation database
As @ZachTeitler pointed out by quoting my blog post, one of our new features acted a bit like a bug: *related papers*. We have made adjustments to avoid the "counting with multiplicity" issue, but some unexpected cases still slipped in. 


One of the examples involving Faltings given by @AlekVainshtein had related papers involved. Some of Vainshtein's other examples uncovered a different issue, which had to do with timing of updates. Updates directly related to individual items in the database are done (almost) continuously. Some other tables are updated continuously at Math Reviews, but pushed out to the web less frequently. We have now synced them up. 


As @AlexSuciu pointed out, there were some growing pains when we released the updates to MathSciNet. We completely changed the search software. We had tested it at both the Math Reviews offices and the AMS headquarters in Providence, but nothing provides a stress test like releasing it publicly. People gave us great feedback, especially about citations, that allowed us to make improvements. 


If you find anything odd, be it citations or something else, you can write to us at either  
 `msn-support@ams.org` or `mathrev@ams.org`. The first address doubles for problems related to access, including subscription problems. The second address doubles as the address reviewers use for communicating with the editorial staff. Both addresses have some traffic direction that will get messages to the right person. 


