Top fields at California Institute of Technology

	Field	Papers	Cites	Cites/paper	Cites/paper world average	% +/–
1	Environment/ecology	133	4,858	36.53	10.24	+257
2	Computer science	485	5,593	11.53	3.32	+247
3	Chemistry	2,010	69,068	34.36	10.26	+235
4	Physics	3,945	101,653	25.77	8.45	+205
5	Materials science	470	8,556	18.20	6.29	+189
6	Engineering	1,683	17,215	10.23	4.	+140
7	Space sciences	5,174	158,583	30.65	13.36	+129
8	Geosciences	1,883	36,899	19.60	8.83	+122
9	Neuroscience	646	25,419	39.35	18.00	+119
10	Biochemistry	884	30,518	34.52	16.09	+115
11	Molecular biology	778	39,875	51.25	24.08	+113
12	Mathematics	663	4,408	6.65	3.15	+111
13	Medicine	333	7,395	22.21	12.02	+85
14	Microbiology	139	3,453	24.84	14.11	+76

The California Institute of Technology (Caltech) in Pasadena was established in 1891 by Amos G. Throop as Throop University. It acquired its present name in 1921. Despite its relatively small size, Caltech is recognised worldwide for its leading role in science and engineering research. Its outsized influence is evident in the 32 Nobel prizes that have been awarded to its faculty and alumni – a disproportionately large number for an institution of Caltech’s size.

The table above lists fields in which Caltech contributed 100 or more research articles or reviews in the jour­nals indexed by Thomson Reuters for its Essential Science Indicators database during the period January 2000 through February 2010. The fields are ranked by relative citation impact, here citations per paper for Caltech in a field compared with citations per paper for the world in the same field. Given the institution’s reputation, it is not surprising to find that in all fields, Caltech’s performance was above the world average – far above, in fact.

With the exception of environment/ecology, ranked first but exhibiting a relatively small paper count, Caltech’s strongest fields represent the physical sciences. The biological sciences appear in the lower half of the table, with the exception of mathematics. However, even Caltech’s lowest ranking field – microbiology – earned it a place in the top 60 institutions worldwide when assessed by relative impact in this area.

Caltech is a classic example of how measures of output and total citations, which are strongly related to output, can be inadequate in revealing excellence in research performance. For small but elite institutions, one must examine the weighted citation impact measure.

For more information on the Thomson Reuters Essential Science Indicators database, see: http://science.thomsonreuters.com/products/esi