Reprinted with permission of

The Scientist 18(11) p.8, June  7 2004

The Myth of Delayed Recognition

Citation analysis demonstrates that premature discovery, while rare, does occur:    Nearly all significant research is normally cited soon after publication

By Wolfgang Glänzel and Eugene Garfield

Most scientists can name an example of an important discovery that had little initial impact on contemporary research. Mendel's work is a classic example.^1,2 The phenomenon of delayed recognition is sometimes invoked in disputes about the validity of citation analysis in evaluating scientists. However, as bibliometricians know, actual examples of delayed recognition are rare.

To identify such papers and to shed some light on their role in scientific communication, we analyzed programmatically the citation histories of the 450,000 research and review articles indexed in the 1980 edition of the Science Citation Index. Delayed recognition papers were defined as those which, during a period of five years, were initially rarely cited but then became highly cited during the next 15 years.³ Highly cited was defined as at least 50 citations or 10 times the journal's 20-year cumulative impact factor.

The chance that a paper, uncited for three to five years after publication, will ever be cited is quite low, even in slowly aging fields such as mathematics. The citation impact of papers not cited initially usually remains low even 15 to 20 years later. Clearly, the potential number of delayed recognition papers is extremely small. Among initially poorly cited papers, only 60 were found that could be considered highly cited during the subsequent 15 years. Thus, a statistically marginal share of 1.3 per 10,000 papers published in 1980 were "neglected" at first, and then, belatedly, received relatively high citational recognition.

But what are these papers about? As expected, most (43%) are life sciences papers, 22% are in physics and 12% each are in chemistry, engineering, and mathematics. Four examples from different science fields are listed below.

1. T. Ogino, M. Aoki, "Mechanism of yellow luminescence in GaN," Jpn J Appl Phys, 19:2395-405, 1980, presented the first in-depth study that explained the mechanism of yellow luminescence in gallium nitride. This paper was only cited twice until 1992. From 1996 onward, it received 20 to 30 citations per year, and the trend still continues with 261 cites to date.

2. K.M. Fabian, "The intra-prostatic partial catheter (urological spiral)," Urologe-Ausgabe A, 19:236-8, 1980, suggested the idea of a temporary urethral stent, and gave a description of the first intraprostatic partial catheter that has become known as the "urological spiral." This paper received only two citations until 1989. Although it was published in German, it was well cited in the 1990s, and has been cited in 105 papers to date.

3. J. Feder, "Random sequential adsorption," J Theor Biol, 87:237-54, 1980. A mathematical paper published in a biology journal, it has been cited in 209 publications to date, especially in physics journals. The author suggested a model to describe protein adsorption on solid surfaces. The random sequential adsorption model has become very popular.

4. G. Buchsbaum, "A spatial processor model for object color-perception," J Franklin Inst, 310:1-26, 1980, gave a clear physical interpretation and mathematical foundation for the 'gray-world' model that is among the most widely cited algorithms in color constancy-related literature. The paper was cited once in 1984 and then in 128 papers after 1988.

Like many myths about the flaws of citation analysis, the claims about delayed recognition are extremely difficult to demonstrate. Each of us has specific examples but, as the data demonstrate, they are indeed the exception to the rule. Nearly all significant research is well cited within the first three to five years of publication.³

Wolfgang Glänzel is senior research fellow, Steunpunt & Statistieken, Katholieke Universiteit Leuven, Belgium.

Eugene Garfield is president and founding editor of The Scientist; he is also chairman emeritus of the Institute for Scientific Information in Philadelphia.

Other examples of delayed recognition, including Inhibin, Scanning Electron Microscopy, and the Genetics of Color Blindness, which were identified by citation analysis, can be found at garfield.library.upenn.edu/delayedrecognition.html