The exponential growth in the number of scientific papers makes it increasingly difficult for researchers to keep track of all the publications relevant to their work. Consequently, the attention that can be devoted to individual papers, measured by their citation counts, is bound to decay rapidly. ... The decay is ... becoming faster over the years, signaling that nowadays papers are forgotten more quickly. However, when time is counted in terms of the number of published papers, the rate of decay of citations is fairly independent of the period considered. This indicates that the attention of scholars depends on the number of published items, and not on real time.Below the fold, some thoughts.
Their analysis is similar to many earlier analyses of the attention decay of general online content, except that their statistics aren't as good:
one cannot count on the high statistics available for online contents: the number of tweets posted on a single popular topic may exceed the total number of scientific publications ever made.Nevertheless, the similarity between the attention decay of papers and that of online content in general is striking. They argue:
Hence, the process of attention gathering needs to take into account the increasing competition between scientific products. With the increase of the number of journals and increasing number of publications in each journal ..., a scientist inevitably needs to filter where to allocate its attention, i.e. which papers to cite, among an extremely broad selection. This may also question whether a scientist is actually fully aware of all the relevant results available in scientific archives. Even though this effect is partially compensated by the increase of the average number of references, one needs to consider the impact of increasing publication volume on the attention decay.They conclude:
The existence of many time-scales in citation decay and our ability to construct an ultrametric space to represent this decay, leads us to speculate that citation decay is an ultradiffusive process, like the decay of popularity of online content. Interestingly, the decay is getting faster and faster, indicating that scholars “forget” more easily papers now than in the past. We found that this has to do with the exponential growth in the number of publications, which inevitably accelerates the turnover of papers, due to the finite capacity of scholars to keep track of the scientific literature. In fact, by measuring time in terms of the number of published works, the decay appears approximately stable over time, across disciplines, although there are slight monotonic trends for Medicine and Biology.Clearly, the response to this problem should not be for publishers to return to their role as gatekeepers, publishing only the good stuff. Research has conclusively shown that they are unable to recognize the good stuff well enough. Rather, in a world where everything gets published, the only question is where it gets published, and the where is not a reliable indicator of quality, we need to stop paying publishers vast sums for minimal value add, and devote the funds to better search, annotation and reputation tools.