Very interesting result, and it makes you feel really sorry that most of those old papers are behind paywalls. (Incidentally, this is a problem which is not going to get solved even if everyone switched to open-access venues today.)<p>Just a comment though: not all citations are equal, so just counting them is quite a crude metric. For instance, a lot of citations in my field (theoretical CS) are "attribution citations" that point the reader to the original paper that introduced a concept or proved a result; and these are not the same as citations of work that you actually extend, or to which you compare.<p>As in theoretical CS things progress fast and people usually improve upon fairly recent works, my feeling (not backed up by data) is that most citations of work older than 10 years are attribution citations; and for attribution, you don't really need to have read the original paper, you just need to know what it introduced or proved. So maybe the Web is making it easier to look up older papers and cite them, but it doesn't mean that the older paper will influence your research beyond adding a bibliographical entry.<p>You could say those additional cites may be useful to the reader, but even then, readers unfamiliar with a concept would often do better to find a recent survey about the concept, rather than try to understand the original paper that introduced it. (The original paper is usually hard to read because it is old and language and notation have changed; and people probably didn't have a good understanding of the concept when they introduced it.) So those citations are mostly for courtesy.
<i>“Our analysis indicates that, in 2013, 36% of citations were to articles that are at least 10 years old and that this fraction has grown 28% since 1990,”</i><p>Put another way, in 1990, 28% of citations were to articles that are at least 10 years old. (28*1.28 = 36). So, in 1990 a significant number of citations were already older papers.<p>I wonder if there is a way to weight individual citations within each work (e.g., by age of the paper cited?) to further strengthen the signal.<p>Also, at some point, the fraction of old papers cited should approach 0% (the fields had to start sometime). It would be interesting to reproduce this analysis for time bins which are older. I presume one would find that the fraction of citations that are to papers 10 years or older would be a monotonically increasing function of time. So one then needs to ask if this increase is due to better access to articles or if it is simply due to there being a larger body of work which is older than 10 years?
So here is one definition of culture, emphasis mine:<p>> "Culture refers to the <i>cumulative deposit of knowledge</i>, experience, beliefs, values, attitudes, meanings, hierarchies, religion, notions of time, roles, spatial relations, concepts of the universe, and material objects and possessions acquired by a group of people in the course of generations through individual and group striving."[1]<p>With that in mind, this development can only be a good thing. I wonder if it measurably speeds up scientific developments? If time and energy don't have to be spent rediscovering something, the more it can be spent on building on the existing knowledge instead.<p>[1] <a href="http://www.tamu.edu/faculty/choudhury/culture.html" rel="nofollow">http://www.tamu.edu/faculty/choudhury/culture.html</a>
Perhaps quality of recent scientific research volume has not increased as much as quantity, so the importance of each individual research piece is lower. Also, selection bias at work: like hit music, only the good stuff still gets played, and if there is sea of lower quality new work, the old foundational classics will be favoured now that they are more easily found.<p>This helps with a dilemma I often face - that of buying recent or older works on Amazon or elsewhere. Instead of always buying the most recent publications on a topic, why not buy the axiomatic decades old works.... indeed in my collection I often find these display more information density, and higher clarity of thought: the latter being inversely proportional to ease with which a document can be produced.
The alternative explanation to easier access is "great stagnation." Discovery is slowing down, low hanging fruit has been picked, so older papers are relatively more important than they used to be.
>>this fraction has grown 28% since 1990<p>Is 28% growth over 25 years significant? How did the growth in the last 10 years look? Somehow the algebra in the article makes for a far more moot point.
At least for me, the title was a bit confusing. It's not the "History of Science" as a subject of study in and of itself or a specific academic field, but rather the large corpus of existing results and publications that's having an effect.<p>I find this distinction very important, because it helps separate the immediate process of science--the people, the historical quirks--from the actual results. It's not a perfect division, of course, but I think it's pretty good in most scientific fields and also very important. It helps distance science, the cumulative understanding of our world, from the people who produced it who are, after all, just human. In my view, this is the main goal of the scientific process, so it's just another component of what makes science <i>science</i>.<p>This is also not to say that the history of science is not interesting or worth studying on its own, merely that it is something largely distinct from the underlying science itself and should ideally be kept that way.