In a new commentary in Water Resources Research, a group of researchers [Heistermann et al., 2014] examined the number and age of citations in water resource journals. They found that that the number of citations per paper has more than tripled over the previous forty years (from about 10 to more than 35), while the age of the cited papers has steadily increased. [They also found that the second most cited research paper is van Genuchten : A closed-form equation for predicting the hydraulic conductivity of unsaturated soils, Soil Sci. Soc. Am. J., which I must confess I have cited regularly].
On one hand, it could be argued that the original papers significantly advanced the field, whereas the later papers only provided incremental advancements at best, so the ground-breaking classics should be given their due. On the other hand, it can also be argued that being faced with an ever-evolving canon of literature, scientists as a whole find it easier to rely on the proven classics rather than sift through the myriad of new publications trying to find the truly unique and impactful among them.
I will admit I have been guilty of over-reliance on the classic papers, for what in all honesty is likely a combination of both reasons listed above. More recently, I have made a concentrated effort to keep abreast of the recent literature, and to incorporate that knowledge and those citations into my own work. This has two real advantages: 1) it helps to ensure that I am truly working on the cutting edge of knowledge; and 2) it hopefully allows these researchers easier access to my own work, through dynamic (forward- and backward-tracking) citation tools such as Google Scholar and Web of Science. I will admit, however, that it is not easy to do so.
One strategy that I have undertaken is signing up for table of contents alerts for the journals that are most relevant to my work. However, this means that every week I get at least one (and often two or three) email from each journal filled with up to 50 new papers. Indeed, some days I feel as if my main job is to read (okay, okay, skim through) other people’s work. It can quickly become overwhelming, and I often worry that with so much new information to process in such a hurry, very little of it can be retained. Nonetheless, I have already had a number of instances either where I immediately recognized that a new publication tied in well with something that I am already working on, or where I have been working on a project or paper and suddenly recall that I have recently come across something similar.
I know from my own experience as a student, as well as observing other students, that first understanding and then keeping current with the literature may be some of the biggest challenges of grad school. Even now, I certainly do not understand all of the intricacies of the soil science and water resources literature, nor have I mastered the techniques of staying current and immersed. I will say, though, that it does continue to get easier with practice (like most anything, I suppose).
As a final word of advance, particularly to grad students: find a copy of Endnote (beg your advisor, your department, or even splurge for it yourself) and learn how to use it. Set up categories for your research topics. Download and index papers. Learn how to “Cite as you write” in Microsoft Word (if that’s your program of choice). With the combination of Endnote and research journal notifications, I feel that it is at least possible to try and stay on top of the literature. And maybe if this practice becomes widespread, as a discipline we can help prevent our citations lists from becoming eligible to collect Social Security.
Gingras, Y., V. Larivière, and É. Archambault (2009), Literature citations in the internet era, Science, 323(5910), 36.
Heistermann, M., T. Francke, C. Georgi, and A. Bronstert (2014), Increasing life expectancy of water resources literature, Water Resour. Res.
Larivière, V., É. Archambault, and Y. Gingras (2008), Long‐term variations in the aging of scientific literature: From exponential growth to steady‐state science (1900–2004), Journal of the American Society for Information Science and technology, 59(2), 288-296.