Wikipedia: A quantitative analysis

Abstract

Presently, the Wikipedia project lodges the largest collaborative community ever known in the history of mankind. Due to the large number of contributors, along with the amazing popularity level of Wikipedia in the Web, it has soon become a topic of interest for researchers of many academic disciplines. However, in spite of the increasing significance of Wikipedia in scholar publications over the past years, we oftenly find studies concentrating either on very specific aspects of the project, or else, on a specific language version. As a result, there is a need of broadening the scope of previous research works to present a more complete picture of the Wikipedia project, its community of contributors and the evolution of this project over time. This doctoral thesis offers a quantitative analysis of the top ten language editions of Wikipedia, from different perspectives. The main goal has been to trace the evolution in time of key descriptive and organizational parameters of Wikipedia and its community of authors. The analysis is focused on logged authors (those editors who created a personal account to participate in the project). The comparative study encompasses general evolution parameters, a detailed analysis of the inner social structure and stratification of the Wikipedia community of logged authors, a study of the inequality level of contributions (among authors and articles), a demographic study of theWikipedia community and some basic metrics to analyze the quality of Wikipedia articles and the trustworthiness level of individual authors. This work concludes with the study of the influence of the main findings presented in this thesis for the future sustainability of Wikipedia in the following years. The analysis of the inequality level of contributions over time, and the evolution of additionalkey features identified in this thesis, reveals an untenable trend towards progressive increase of the effort spent by the most active authors, as time passes by. This trend may eventually cause that these authors will reach their upper limit in the number of revisions they can perform each month, thus starting a decreasing trend in the number of monthly revisions, and an overall recession of the contentcreation and reviewing process in Wikipedia. Finally, another important contribution for the research community is WikiXRay, the software tool we have developed to perform the statistical analyses included in this thesis. This tool completely automates the process of retrieving the database dumps from theWikimedia public repositories, massaging it to obtain key metrics and descriptive parameters, and loading them in a local database, ready to be used in empirical analyses. As far as we know, this is the first research work implementing a comparative analysis, from an quantitative point of view, of the top ten language editions of Wikipedia, presenting complementaryresults from different research perspectives. Therefore, we expect that this contribution will help the scientific community to enhance their understanding of the rich, complex and fascinating working mechanisms and behavioral patterns of theWikipedia project and its community of authors. Likewise, we hope thatWikiXRay will facilitate the hard task of developing empirical analyses on any language version of the encyclopaedia, boosting in this way the number of comparative studies like this one in many other scientific disciplines.