El Diario de Pontevedra : periódico liberal: Ano XXXI Número 9129 - 1914 outubro 5

<p>Regression of articles’ imbalance on relevant predictors and their interactions with the dummy-coded direction of article polarity (estimates in parentheses result if the dummy variable for direction gets a value of zero, instead of one, for articles with pro-conventional perspectives).</p

A productive clash of perspectives? The interplay between articles’ and authors’ perspectives and their impact on Wikipedia edits in a controversial domain

<div><p>This study examined predictors of the development of Wikipedia articles that deal with controversial issues. We chose a corpus of articles in the German-language version of Wikipedia about alternative medicine as a representative controversial issue. We extracted edits made until March 2013 and categorized them using a supervised machine learning setup as either being <i>pro conventional medicine</i>, <i>pro alternative medicine</i>, or <i>neutral</i>. Based on these categories, we established relevant variables, such as the perspectives of articles and of authors at certain points in time, the (im)balance of an article’s perspective, the number of non-neutral edits per article, the number of authors per article, authors’ heterogeneity per article, and incongruity between authors’ and articles’ perspectives. The underlying objective was to predict the development of articles’ perspectives with regard to the controversial topic. The empirical part of the study is embedded in theoretical considerations about editorial biases and the effectiveness of norms and rules in Wikipedia, such as the neutral point of view policy. Our findings revealed a selection bias where authors edited mainly articles with perspectives similar to their own viewpoint. Regression analyses showed that an author’s perspective as well as the article’s previous perspectives predicted the perspective of the resulting edits, albeit both predictors interact with each other. Further analyses indicated that articles with more non-neutral edits were altogether more balanced. We also found a positive effect of the number of authors and of the authors’ heterogeneity on articles’ balance. However, while the effect of the number of authors was reserved to pro-conventional medicine articles, the authors’ heterogenity effect was restricted to pro-alternative medicine articles. Finally, we found a negative effect of incongruity between authors’ and articles’ perspectives that was pronounced for the pro-alternative medicine articles.</p></div

Observed frequencies and expected frequencies (in brackets) for the combination of articles’ polarity scores (rows) and authors’ polarity scores (columns).

<p>Observed frequencies and expected frequencies (in brackets) for the combination of articles’ polarity scores (rows) and authors’ polarity scores (columns).</p

Polarity development of those <i>n</i> = 47 articles that contained at least 100 non-neutral edits.

<p>Each curve represents the polarity development of a particular article. For the 100th edit, the averaged polarity of those articles is <i>M</i> = 0.54 (<i>SD</i> = 0.08). The two bold green lines represent a 95% binomial proportion confidence interval, calculated by the method of Wilson [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178985#pone.0178985.ref057" target="_blank">57</a>] without continuity correction, with a 54 percent probability of success (e.g., observing head in a random experiment with a slightly biased coin). The bold line in black represents the theoretical midpoint (0.50) of the polarity scale. The other two bold lines represent the value 0.54 (blue) and the cross-sectional mean values (orange).</p

Frequencies of (non-neutral) edits as a function of the incongruity between an articles’ polarity (weighted average of all previous non-neutral edits in the article) and the polarity of the editing author (average of all non-neutral edits an author had performed before).

<p>Frequencies of (non-neutral) edits as a function of the incongruity between an articles’ polarity (weighted average of all previous non-neutral edits in the article) and the polarity of the editing author (average of all non-neutral edits an author had performed before).</p