Active learning strategies for solving the cold user problem in model-based recommender systems

Article type: Research Article

Authors: Geurts, Tomas | Giannikis, Stelios | Frasincar, Flavius^{; *}

Affiliations: Erasmus University Rotterdam, Burgemeester Oudlaan 50, 3062 PA, Rotterdam, The Netherlands. E-mails: tomasgeurts92@gmail.com, steliosgiannik@gmail.com, frasincar@ese.eur.nl

Correspondence: [*] Corresponding author. E-mail: frasincar@ese.eur.nl.

Abstract: Customers of a webshop are often presented large assortments, which can lead to customers struggling finding their desired product(s), an issue known as choice overload. In order to overcome this issue, recommender systems are used in webshops to provide personalized product recommendations to customers. Though, model-based recommender systems are not able to provide recommendations to new customers (i.e., cold users). To facilitate recommendations to cold users we investigate multiple active learning strategies, and subsequently evaluate which active learning strategy is able to optimally elicit the preferences from the cold users in a matrix factorization context. Our model is empirically validated using a dataset from the webshop of de Bijenkorf, a Dutch department store. We find that the overall best-performing active learning strategy is PopError, an active learning strategy that measures the variance score for each item.

Keywords: Collaborative filtering, matrix factorization, active learning

DOI: 10.3233/WEB-210448

Journal: Web Intelligence, vol. 18, no. 4, pp. 269-283, 2020