Nicolas Mattis


Implementing Evaluation Metrics Based on Theories of Democracy in News Comment Recommendation (Hackathon Report)
Myrthe Reuver | Nicolas Mattis
Proceedings of the EACL Hackashop on News Media Content Analysis and Automated Report Generation

Diversity in news recommendation is important for democratic debate. Current recommendation strategies, as well as evaluation metrics for recommender systems, do not explicitly focus on this aspect of news recommendation. In the 2021 Embeddia Hackathon, we implemented one novel, normative theory-based evaluation metric, “activation”, and use it to compare two recommendation strategies of New York Times comments, one based on user likes and another on editor picks. We found that both comment recommendation strategies lead to recommendations consistently less activating than the available comments in the pool of data, but the editor’s picks more so. This might indicate that New York Times editors’ support a deliberative democratic model, in which less activation is deemed ideal for democratic debate.

Are we human, or are we users? The role of natural language processing in human-centric news recommenders that nudge users to diverse content
Myrthe Reuver | Nicolas Mattis | Marijn Sax | Suzan Verberne | Nava Tintarev | Natali Helberger | Judith Moeller | Sanne Vrijenhoek | Antske Fokkens | Wouter van Atteveldt
Proceedings of the 1st Workshop on NLP for Positive Impact

In this position paper, we present a research agenda and ideas for facilitating exposure to diverse viewpoints in news recommendation. Recommending news from diverse viewpoints is important to prevent potential filter bubble effects in news consumption, and stimulate a healthy democratic debate.To account for the complexity that is inherent to humans as citizens in a democracy, we anticipate (among others) individual-level differences in acceptance of diversity. We connect this idea to techniques in Natural Language Processing, where distributional language models would allow us to place different users and news articles in a multidimensional space based on semantic content, where diversity is operationalized as distance and variance. In this way, we can model individual “latitudes of diversity” for different users, and thus personalize viewpoint diversity in support of a healthy public debate. In addition, we identify technical, ethical and conceptual issues related to our presented ideas. Our investigation describes how NLP can play a central role in diversifying news recommendations.