The Number of Scholarly Documents on the Public Web

Abstract

The number of scholarly documents available on the web is estimated using capture/recapture methods by studying the coverage of two major academic search engines: Google Scholar and Microsoft Academic Search. Our estimates show that at least 114 million English-language scholarly documents are accessible on the web, of which Google Scholar has nearly 100 million. Of these, we estimate that at least 27 million (24%) are freely available since they do not require a subscription or payment of any kind. In addition, at a finer scale, we also estimate the number of scholarly documents on the web for fifteen fields: Agricultural Science, Arts and Humanities, Biology, Chemistry, Computer Science, Economics and Business, Engineering, Environmental Sciences, Geosciences, Material Science, Mathematics, Medicine, Physics, Social Sciences, and Multidisciplinary, as defined by Microsoft Academic Search. In addition, we show that among these fields the percentage of documents defined as freely available varies significantly, i.e., from 12 to 50%.

Do you speak open science? Resources and tips to learn the language

“…As a general rule, it is important to remember that the use of licenses which limit commercial re-use or limit the production of derivative works by excluding use for specific purposes is discouraged. This because these licenses can make it quite a bit harder to effectively re-use datasets, and could also prevent (tangential) commercial activities that could be used to support data preservation in the longterm 5 . Share the metadata along with the data.…”

“…In his review of Michael Neilsen's book "Reinventing Discovery" [3], Timo Hannay describes science as "self-serving" and "uncooperative", "replete with examples of secrecy and resistance to change", and furthermore defines the natural state of researchers as "one of extreme possessiveness" [4]. Hannay might have a point: the majority of research papers are behind a paywall [5], researchers still fail at making data and metadata available [6], reproducibility is hampered by the lack of appropriate reporting of methodologies [7], software is often not released [8], and peer-review is anonymous and slow [9].…”

Scholia, Scientometrics and Wikidata

“…By using these properties systematically according to an emerging data model, 13 editors have extended the bibliographic information in Wikidata. Particularly instrumental in this process was a set of tools built by Magnus Manske, QuickStatements 14 and Source MetaData, 15 Given that Wikidata only has around 3.4 million P2860-citations, it is no surprise that the current number of citations is considerable less than the citation counts one finds in other web services, -even for authors with a large part of their published scientific articles listed in Wikidata.…”

JournalGuide: bringing authors and journals together

“…Biomedical fields are heavily represented, likely reflecting the large proportion of published papers in those areas. 7 Article metadata for comparison is captured from various sources, including PubMed, CrossRef, and directly from a number of publishers and aggregators. Upon searching, JournalGuide returns a list of journals where similar articles have been published, meaning that they are well matched in scope to the user's manuscript or keywords.…”