n the following page Science Watch features a listing of the five institutions that have been most cited in each of 18 fields in the last decade (1991-February 2001). These are the heavy hitters of science. In general, each not only published in quantity but also exerted outsized influence on the world's research community, as reflected in their tremendous citation tallies.

To compile these rankings, Science Watch turned to ISI Essential Science Indicators (ESI), a new web database covering upwards of 7 million articles in 22 broad fields of the sciences and social sciences. Each field is defined by a set of journals, all indexed by ISI. ESI will henceforth be updated every two months.

These rankings, as mentioned, are based on total citations. It should be noted that this measure, in contrast to a ranking by citations per paper (impact), tends to favor larger institutions that produce many research papers. So, these institutions—universities, government labs, and corporations—are tops in terms of gross influence, whereas others may score higher in impact, a measure of weighted influence.

Of all the institutions listed, none fared better than Harvard University, which appeared in 8 of the 18 rankings—and in the top spot in all but one of those fields. In particular, Harvard showed its citation preeminence in biomedical fields, including biology & biochemistry, clinical medicine, molecular biology & genetics, and immunology. Harvard, of course, dominated this publication's most recent roundup of U.S. university research three years ago (see Science Watch, 9[5]:1-2, September/October 1998; 9[6]:1-2, November/December 1998), so its strong showing here is certainly not unexpected. This time, however, Harvard shines on the world stage. Close behind, with a top-five showing in seven fields, is the University of Texas System.

With five appearances, MIT showed predictable strength in physical sciences such as engineering, materials, physics, and computer science. The University of California at Berkeley also logged five appearances, including the top spot in chemistry and a #2 berth in engineering. The National Cancer Institute, meanwhile, made four of the biomedical rankings.

Among non-U.S. institutions, the University of Tokyo achieved distinction, ranking in the top five in physics, chemistry, and biology & biochemistry. Two national agencies—France's INRA (Institute National de la Recherche Agronomique) and Australia's CSIRO (Commonwealth Scientific and Industrial Research Organisation)— also accounted for two appearances each.

  View the listing of the five institutions that have been most cited in each of 18 fields in the last decade (1991-February 2001).