University of Amsterdam at CLEF 2020 Notebook for the Touché Lab on Argument Retrieval at CLEF 2020

This paper documents the University of Amsterdam’s participation in CLEF 2020 Touché Track. This is the first year this track has been introduced at CLEF, and we were attracted to participate in it due to its potentialities for Parliamentary debates we are currently working on. This track consists of two tasks: Conversational Argument Retrieval and Comparative Argument Retrieval.
We submitted a run to both tasks. For the first task, we used a combination of the traditional BM25 model and learning to rank models. BM25 model helps to retrieve relevant arguments, and learning to rank model helps to re-rank the list and put stronger arguments on top of the list. For the second task, Comparative Argument Retrieval, we proposed a pipeline to re-rank documents retrieved from Clueweb using three features: PageRank scores, web domains, and argumentativeness. Preliminary results on 5 queries have shown that this heuristic pipeline may help to achieve a balance among three important dimensions: relevance, trustworthiness, and argumentativeness.