Odi et Amo. Creating, Evaluating and Extending Sentiment Lexicons for Latin

Sentiment lexicons are essential for developing automatic sentiment analysis systems, but the resources currently available mostly cover modern languages. Lexicons for ancient languages are few and not evaluated with high-quality gold standards. However, the study of attitudes and emotions in ancient texts is a growing field of research which poses specific issues (e.g., lack of native speakers, limited amount of data, unusual textual genres for the sentiment analysis task, such as philosophical or documentary texts) and can have an impact on the work of scholars coming from several disciplines besides computational linguistics, e.g. historians and philologists. The work presented in this paper aims at providing the research community with a set of sentiment lexicons built by taking advantage of manually-curated resources belonging to the long tradition of Latin corpora and lexicons creation. Our interdisciplinary approach led us to release: i) two automatically generated sentiment lexicons; ii) a Gold Standard developed by two Latin language and culture experts; iii) a Silver Standard in which semantic and derivational relations are exploited so to extend the list of lexical items of the Gold Standard. In addition, the evaluation procedure is described together with a first application of the lexicons to a Latin tragedy.