Editorial pubs.acs.org/cm
The Impact of the Impact Factor strongly believe that these fluorescent carbon dots are incredibly interesting, how many citations will this, or any published manuscript, expect to accumulate over its lifetime? This topic is the subject of a thought-provoking paper in Science, published in October of 2013, entitled “Quantifying Long Term Scientific Impact”, by Wang, Song, and Barabási.4,5 In this work, the authors developed a model to predict the long-term impact of a publication, regardless of subject area, author identities, and the journal in which it was published. By mathematically correcting for the three important underlying factors that contribute to the overall citation rate of a particular paperthe rate of initial growth (of citations), the appeal of the paper, and the decay rate (of citations) over timethey developed a model that predicts the number of lifetime citations that particular manuscript would be expected to receive. Interestingly, 93.5% of papers examined fell within the prediction envelope, based upon the number of citations accrued over the first 5 years since publication, up to 25 years into the future (Figure 2a); 10 years of accumulated citations was even more accurate (Figure 2b).4 The model is not perfect, as it cannot account for “exogenous second acts”,4 such as those when a piece of work becomes instrumental in the growth of a new field or area; the authors have indicated that they plan to increase the complexity of the model to improve upon it. The model does, however, raise very interesting questions regarding the accuracy of “citation-based impact”, such as the Hirsch-factor (h-factor) for individual researchers and the impact factor (IF) of a journal. In the case of the IF, only the prior two years’ worth of citations are used, and if a publication is ahead of its time (as was noted for one of the journals evaluated in the Science publication), this number may, in fact, have little meaning except as a short-term indicator; the long-term impact may be wildly different than that expected from the 2-year IF. As most of the tenure and promotions processes of academia relies upon citation-based impact, it is worth carefully considering what these numbers truly mean, although this is certainly part of a long-term discussion. So, to bring us back to our most highly downloaded publications page on the Chemistry of Materials website, we recognize that this snapshot in time of what papers are the most highly downloaded is not a predictor of future citation numbers. We do, however, find value in this feature since it allows us to peek into the mindset of our readers, at a given moment in time. Our task as editors and staff at Chemistry of Materials is to be open to new areas of research, to maintain very high standards for our readers, and to respond quickly to authors and to new developments in the field. We cannot control, or predict, the long-term citation counts of the papers we publish, but we can ensure that we support the publication of creative, carefully executed papers that resonate with us as practicing scientists. On another note, it is our pleasure to announce that Ram Seshadri, Professor at the Materials Research Laboratory (MRL) at the University of California, Santa Barbara, has joined us as an associate editor at Chemistry of Materials, starting July 1, 2014
At the beginning of each month, I look forward to the updating of our Most Read Articles feature on the website, which lists our most highly downloaded papers from the previous month.1 The papers point to the areas that are attracting a great deal of research interest and attention, and it is curious to observe a mix of very new papers (some are still ASAPs), while others have been published for over a decade. For instance, our top most highly downloaded paper for May of 2014 is a beautiful piece of work by Li and Zhang of Jilin University on fluorescent carbon dots in issue no. 10 of this year, of which the table of contents (ToC) image is shown as Figure 1a.2 Another paper in our top 10
Figure 1. Table of contents (ToC) images for two of our most highly downloaded papers in May of 2014. (a) The most highly downloaded paper in May;2 (b) another of our top 10 most highly downloaded papers in May, published in 2003.3 Figures reprinted with permission. Copyright 2014 (a) and 2003 (b) American Chemical Society.
most highly downloaded papers for May is the now classic treatise by Nikoobakht and El-Sayed on the synthesis of gold nanorods using a seed method (ToC image in Figure 1b) that was published in 2003.3 What is it about this El-Sayed paper that gives it such longevity, and was it obvious over a decade ago that this paper would have such a long-term impact? While we © 2014 American Chemical Society
Published: July 8, 2014 3871
dx.doi.org/10.1021/cm502204r | Chem. Mater. 2014, 26, 3871−3872
Chemistry of Materials
Editorial
Figure 2. Model from ref 4 predicting total citations of a paper based upon (a) 5 years of citation data and (b) 10 years of citation data. Figure reproduced with permission. Copyright 2013 American Association for the Advancement of Science.
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(pictured in Figure 3). Ram has incredible breadth of experimental research expertise, from solid state materials for
REFERENCES
(1) http://pubs.acs.org/action/showMostReadArticles?journalCode=cmatex&topArticlesType=month. (2) Nie, H.; Li, M.; Li, Q.; Liang, S.; Tan, Y.; Sheng, L.; Shi, W.; Zhang, S. X.-A. Chem. Mater. 2014, 26, 3104. (3) Nikoobakht, B.; El-Sayed, M. A. Chem. Mater. 2003, 15, 1957. (4) Wang, D.; Song, C.; Barabási, A.-L. Science 2013, 342, 127. (5) Van Noorden, R. Nature News 2013, DOI: 10.1038/nature.2013.13881.
Figure 3. Ram Seshadri, new associate editor at Chemistry of Materials as of July, 2014.
lighting, to catalysis, to materials for energy, to proficiency in computational materials science. Welcome, Ram, to Chemistry of Materials.
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Jillian M. Buriak, Editor-in-Chief AUTHOR INFORMATION
Notes
Views expressed in this editorial are those of the author and not necessarily the views of the ACS. 3872
dx.doi.org/10.1021/cm502204r | Chem. Mater. 2014, 26, 3871−3872
