negotiated a version of the article that both can more or less live with". The author comments that: Shi et al. extended this analysis in discussing "The wisdom of polarized crowds" in 2017 based on content analysis of all edits to English Wikipedia articles relating to politics, social issues and science from its start to December 1, 2016. This included almost 233,000 articles representing approximately 5 percent of the English Wikipedia. They wrote: "Political speech [at least in the United States] has become markedly more polarized in recent years ... . [D]espite early promise of the world-wide-web to democratize access to diverse information, increased media choice and social networking platforms ... [create] echo chambers that ... degrade the quality of individual decisions, ... discount identity-incongruent opinions, stimulate and reinforce polarizing information ... foment conflict and even make communication counter-productive. Nevertheless, a large literature documents the largely positive effect that social differences can exert on the collaborative production of information, goods and services. Research demonstrates that individuals from socially distinct groups embody diverse cognitive resources and perspectives that, when cooperatively combined ... outperform those from homogeneous groups." They translated edit histories of millions of Wikipedia editors into a 7-point political identification scale and compared that with Wikipedia's six-level article quality score (stub, start, C, B, good, featured) assigned via a machine learning algorithm. They found that "articles attracting more attention tend to have more balanced engagement ... [and] higher polarization is associated with higher quality." Academia Academics have also criticized Wikipedia for its perceived failure as a reliable source and because Wikipedia editors may have no expertise, competence, or credentials in the topics on which they contribute. Adrian Riskin, a mathematician in Whittier College commented that while highly technical articles may be written by mathematicians for mathematicians, the more general maths topics, such as the article on polynomials, are written in a very amateurish fashion with a number of obvious mistakes. Because Wikipedia cannot be considered a reliable source, the use of Wikipedia is not accepted in many schools and universities in writing a formal paper, and some educational institutions have banned it as a primary source while others have limited its use to only a pointer to external sources. The criticism of not being a reliable source, however, may not only apply to Wikipedia but to encyclopedias in general—some university lecturers are not impressed when students cite print-based encyclopedias in