We first adopt a human-guided machine learning framework to develop a new dataset for hyperpartisan news title detection with 2,200 manually labeled and 1.8 million machine-labeled titles that were posted from 2014 to the present by nine representative media organizations across three media bias groups - Left, Central, and Right in an active learning manner. The fine-tuned transformer-based language model achieves an overall accuracy of 0.84 and an F1 score of 0.78 on an external validation set. Next, we conduct a computational analysis to quantify the extent and dynamics of partisanship in news titles. While some aspects are as expected, our study reveals new or nuanced differences between the three media groups. We find that overall the Right media tends to use proportionally more hyperpartisan titles. Roughly around the 2016 Presidential Election, the proportions of hyperpartisan titles increased in all media bias groups where the relative increase in the proportion of hyperpartisan titles of the Left media was the most. We identify three major topics including foreign issues, political systems, and societal issues that are suggestive of hyperpartisanship in news titles using logistic regression models and the Shapley values. Through an analysis of the topic distribution, we find that societal issues gradually receive more attention from all media groups. We further apply a lexicon-based language analysis tool to the titles of each topic and quantify the linguistic distance between any pairs of the three media groups. Three distinct patterns are discovered. The Left media is linguistically more different from Central and Right in terms of foreign issues. The linguistic distance between the three media groups becomes smaller over recent years. In addition, a seasonal pattern where linguistic difference is associated with elections is observed for societal issues.

本文采取人工辅助机器学习框架，针对具有代表性的3个主流媒体倾向组（左，中，右）在2014年至今发布的2.2万份手动标记和180万份机器标记的新闻标题进行了超党派新闻标题检测的数据集开发，并在外部验证集上取得了0.84的准确度和0.78的F1得分；针对新闻标题中的党派性进行了计算分析，发现右翼媒体倾向于使用比例更高的超党派标题；通过逻辑回归模型和Shapley值确定了几个主题，并应用基于词库的语言分析工具对每个主题的标题进行了分析，发现左派、中派和右派媒体在外交、政治和社会问题方面的语言差异逐渐减小。

新闻标题中的超级党派性的计算评估