As the number and range of research projects continue to grow, reference citations have come to play more important roles in establishing the relative merits of those projects. Of course, many readers seized on Sidney Redner’s study of citation statistics (June 2005, page 49) to see “how well” they are doing personally, but many others must have viewed his results as evaluative on a larger scale. Just how significant are citations?
Speaking for my own interests, I could scarcely be unhappy. Among the top 10 “hot” papers on Redner’s list (page 51), 6 are in the field of electronic structure calculations, in which I did my 15 years of research long, long ago. The amazing popularity of that field is explicable in many ways. The methods developed by physicists are extremely accurate and have been widely adopted by chemists, who contribute most of the citations. The new methods are transparent, reliable, transferable, and available in user-friendly packages. Physicists can be proud of having taken such fascinating and complex problems and rendered them readily accessible to researchers who have many other responsibilities.
Still, some aspects of the citation game are disappointing. All the top 10 papers are theoretical. Does this mean that experimental physics is dying? No, it just means that citations don’t mean so much, and they should not be used to measure impact or importance of a field or as a facile substitute for understanding how science grows and develops. Citations reflect many incidental factors, including the wish to conform to standard practice, and even reflect the convenience of citing a previously cited paper (without reading it). Experimental discoveries, often published in specialized journals, are still by far the most important part of physics, regardless of how many citations a single paper receives in Physical Review.
