 They noted that at least in the US, 

They translated edit histories of millions of Wikipedia editors into a 7-point political identification scale and compared that with Wikipedia's 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.”

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.