Is Wikipedia Politically Biased?

Wikipedia.org is the seventh-most visited domain on the World Wide Web but its significant has grown beyond its direct human readership, as its content is routinely employed in the training of Large Language Models (LLMs) such as ChatGPT. Consequently, any biases present in Wikipedia’s content may be absorbed into the parameters of contemporary AI systems, potentially perpetuating and amplifying these biases. This work aims to determine whether there is evidence of political bias in English-language Wikipedia articles. The goal of this report is to complement the literature on Wikipedia’s political bias by using a novel methodology—computational content analysis using modern LLMs for content annotation—to assess quantitatively whether there is political bias in Wikipedia’s content. Specifically, we computationally assess the sentiment and emotional tone associated with politically charged terms—those referring to politically aligned public figures and institutions—within Wikipedia articles.