Scientific citations in Wikipedia

The Internet-based encyclopædia Wikipedia has grown to become one of the most visited web-sites on the Internet. However, critics have questioned the quality of entries, and an empirical study has shown Wikipedia to contain errors in a 2005 sample of science entries. Biased coverage and lack of sources are among the “Wikipedia risks”. The present work describes a simple assessment of these aspects by examining the outbound links from Wikipedia articles to articles in scientific journals with a comparison against journal statistics from Journal Citation Reports such as impact factors. The results show an increasing use of structured citation markup and good agreement with the citation pattern seen in the scientific literature though with a slight tendency to cite articles in high-impact journals such as Nature and Science. These results increase confidence in Wikipedia as an good information organizer for science in general. Wikipedia increases in popularity and will probably get further importance for organization and dissemination of scientific research. But how can the articles of this freely edited Internet-based encyclopædia be trusted? Inbound links can to some extent quantify the quality of a work, and examples include Google’s PageRank for web-pages and the impact factor of scientific journals. The algorithms behind the PageRank and Kleinberg’s HITS can be adapted to Wikipedia, but it is not clear whether high-scoring articles are also quality articles with respect to content. It has been suggested that Wikipedia content surviving over a long period and many edits may be deemed of high quality. On the other hand studies have found that highly edited articles are likely quality articles. Other proposals for quality assessment use revision history to compute a trust index for an article or an author reputation index. Another feature of an article that may correlate with article quality is the amount of outbound citation to “trusted” material, e.g., scientific articles. How prolific are these and does Wikipedia use them across scientific fields? Critics have noted that Wikipedia may be biased on the corpus level—leaned towards topics that interest the “young and Internet-savvy”—and a possible lack of sources has been noted. Authors can include scientific references in Wikipedia by different means, most simply, by listing them at the bottom of the article. A more structured approach uses the