Tracking the patterns of influence and prestige that accompany the publication of papers in top scientific journals has become a key to hiring, promotion, and making grants in the sciences, as The Chronicle noted in an October 2005 article. Publishing work in the most prestigious journals—including Science and Nature— carries a numeric value (created by Thomson Scientific, the company that compiles that data). The value is used to rank the importance and “impact” of a scientific article. That number—the “impact factor”—is now used across a wide range of scientific endeavors to evaluate not only work, but individual scientists as well.

As the impact factor increases in importance, the next logical step is determining which individual scientists have the most impact. José Soler, a Spanish statistical physicist, has completed just such a ranking for his discipline, the online news-site PhysicsWeb reports. Mr. Soler came up with his rankings by determining the number of references that a given paper makes to previous papers, and then calculating the number of subsequent references to that paper in other articles. His “creativity index” ranks papers with the fewest references and most citations as the “highest” in creativity.

After calculating scores for the 10 most-cited physicists as ranked by Thomson Scientific, Mr. Soler determined that Philip W. Anderson, a Nobel Prize-winning physicist at Princeton University, had the highest creativity score. Edward Witten, a string theorist at the Institute for Advanced Study, in Princeton, N.J., had the second-highest score. Steven Weinberg, a Nobel winner at the University of Texas at Austin, placed third.