fter appearing to level off earlier in this decade, the number of papers with 50 or more coauthors reached new peaks in recent years, with a notable spike in reports with at least 500 authors, according to a new Science Watch survey.

Science Watch last visited this topic three years ago (15[4]: 1-2, July/August 2004), assessing trends in multiauthor papers from the early 1990s through 2003. At that time, the population of such papers, after exhibiting a high around 1997 or 1998, seemed to be leveling off. To gauge current trends, Science Watch updated the numbers for the last three years in the graph to the left below, enumerating those papers with more than 50, 100, 200, and 500 authors for the years 1993 to 2006. (As in the previous survey, the numbers are cumulative, in that papers with more than 100, 200, and 500 authors are included in the statistics for those with more than 50.)

As the current graph to the left (#1) indicates, the numbers for all four groupings of papers, after largely plateauing from 2000 to 2003, rose sharply in the next couple of years, attaining their highest levels in 2005, with the 50+ contingent registering nearly 750 papers that year. The rise for papers with more than 100 authors was particularly sharp, increasing from just over 300 in 2003 to 475 in 2005. And, although perhaps not as immediately striking on the graph due to its bottom-most position, the population of papers with 500 or more authors made the largest jump of all, increasing by more than 200% from 40 in 2003 to 131 in 2005.

To convey the general makeup of recent multiauthor papers, the top graph (#2) below divides papers with more than 100 authors into two main groupings: physical sciences and biomedicine. The physical-sciences group jumped sharply after 2003, climbing from 249 that year to 393 in 2005. (Of the latter total, 363 papers were categorized in the main field of Physics, with 13 from Space Science and 17 from Engineering.)

By contrast, the graph indicates that biomedicine papers with 100 or more authors have declined in the last couple of years, from 41 in 2004 to 19 in 2006. (The majority of these papers were in Clinical Medicine, with lesser representation from Molecular Biology & Genetics, Microbiology, Neurology, and other fields.)

It remains to be seen, of course, whether such mega-multiauthor papers are anomalies or whether they’ll become increasingly common. Meanwhile, a couple of the general trends mentioned in the previous Science Watch survey have continued: in 2003, for example, the mean number of authors per Thomson Scientific-indexed paper was 3.6 (up from 2.6 in 1990); as of 2006, the figure had edged up to 3.8. And the percentage of single-author papers, 38% in 1990 and just over 25% in 2004, slipped a bit towards 24% in 2006.

On the other hand, as the first two graphs indicate (#1|#2), most of the totals for the assorted groupings of multiauthor papers show a decline for the most-recent year, 2006 (e.g., for papers with more than 50 authors, from 741 to 645). Will 2005 mark some kind of zenith, or merely a brief detour in an ongoing ascent?

Graph #3
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