Detecting Media Bias in News Articles using Gaussian Bias Distributions
This work addresses the issue of biased media influencing public opinion, though it is incremental as it builds on existing sentence-level bias detection methods.
The paper tackled the problem of detecting media bias in news articles by using second-order information about biased statements, such as their frequency and positions, within a Gaussian Mixture Model, resulting in clear performance improvements over methods that rely only on low-level lexical information.
Media plays an important role in shaping public opinion. Biased media can influence people in undesirable directions and hence should be unmasked as such. We observe that featurebased and neural text classification approaches which rely only on the distribution of low-level lexical information fail to detect media bias. This weakness becomes most noticeable for articles on new events, where words appear in new contexts and hence their "bias predictiveness" is unclear. In this paper, we therefore study how second-order information about biased statements in an article helps to improve detection effectiveness. In particular, we utilize the probability distributions of the frequency, positions, and sequential order of lexical and informational sentence-level bias in a Gaussian Mixture Model. On an existing media bias dataset, we find that the frequency and positions of biased statements strongly impact article-level bias, whereas their exact sequential order is secondary. Using a standard model for sentence-level bias detection, we provide empirical evidence that article-level bias detectors that use second-order information clearly outperform those without.