Another means of measuring author authority — or quantifying author contributions — is assessed by Nature associate editor Noah Gray at his Nature Network blog Nothing's Shocking (http://tinyurl.com/66asud). The plan is a formula that provides each author with a rank and fractional credit based on that rank.

Gray points to one of many flaws in such proposals: “An attempt to actually place a value on the number of times you happened to complete some Western blots for a colleague seems to provide false authority where none should lie.” He adds that, at least in biology, it is well known that if an author appears fifth in a list of eight, he or she was not the driving force behind the project.

Almost ten years ago, Nature began to recommend an 'author contributions' paragraph at the end of a manuscript, a popular service useful to authors and readers, although not a panacea for those seeking a simple (and unobtainable) metric. Many discussions on author credit are archived at Nautilus (http://tinyurl.com/6zg2h2).