中文新聞文本之宣傳手法標記與分析

The Analysis and Annotation of Propaganda Techniques in Chinese News Texts

新聞媒體常在政治新聞文本中運用宣傳手法（propaganda techniques）表達媒體本身之政治立場，企圖影響讀者之立場。目前尚無具宣傳手法標記之中文語料供立場分析，本文以可解釋性的方式，人工細部標記中文新聞文本所使用之宣傳手法、並以Bootstrap方式擴展標記規模的資料集，再分別以人工檢核與先導實驗來確保標記資料集之效能。透過單純貝式分類器搭配基本的詞袋特徵進行訓練後，機器判讀行段是否包含宣傳手法的準確率達74.26％。本宣傳手法之人工標記資料已公開釋出，可應用於未來機器訓練與學習預測新文本之立場。

In political news media, propaganda techniques are often employed to express one's political view, or to influence the audience's stance. Chinese corpora with the annotation of propaganda techniques are yet to be developed. In this paper, with an explainable approach, we annotated the use of propaganda techniques in Chinese political news texts, and enlarged the dataset by bootstrapping using a small set of manually annotated data. To ensure the validity, we manually corrected the bootstrapped dataset and ran a pilot machine-learning experiment using a naïve Bayes classifier trained with the bag-of-words feature. A precision of 74.26% was reached for the binary classification (with or without propaganda technique). The manually annotated data with propaganda techniques is available online for the application of machine training and learning to predict the stance of new texts.