On the Importance of Considering Country-specific Aspects on the Online-Market: An Example of Music Recommendation Considering Country-Specific Mainstream

In the field of music recommender systems, country-specific aspects have received little attention, although it is known that music perception and preferences are shaped by culture; and culture varies across countries. Based on the LFM-1b dataset (including 53,258 users from 47 countries), we show that there are significant country-specific differences in listeners’ music consumption behavior with respect to the most popular artists listened to. Results indicate that, for instance, Finnish users’ listening behavior is farther away from the global mainstream, while United States’ listeners are close to the global mainstream. Relying on rating prediction experiments, we tailor recommendations to a user’s level of preference for mainstream (defined on a global level and on a country level) and the user’s country. Results suggest that, in terms of rating prediction accuracy, a combination of these two filtering strategies works particularly well for users of countries far away from the global mainstream

Utilizing Human Memory Processes to Model Genre Preferences for Personalized Music Recommendations

In this paper, we introduce a psychology-inspired approach to model and predict the music genre preferences of different groups of users by utilizing human memory processes. These processes describe how humans access information units in their memory by considering the factors of (i) past usage frequency, (ii) past usage recency, and (iii) the current context. Using a publicly available dataset of more than a billion music listening records shared on the music streaming platform Last.fm, we find that our approach provides significantly better prediction accuracy results than various baseline algorithms for all evaluated user groups, i.e., (i) low-mainstream music listeners, (ii) medium-mainstream music listeners, and (iii) high-mainstream music listeners. Furthermore, our approach is based on a simple psychological model, which contributes to the transparency and explainability of the calculated predictions.Comment: Dominik Kowald and Elisabeth Lex contributed equally to this wor

Investigating cross-country relationship between users' social ties and music mainstreaminess

We investigate the complex relationship between the fac- tors (i) preference for music mainstream, (ii) social ties in an online music platform, and (iii) demographics. We define (i) on a global and a country level, (ii) by several network centrality measures such as Jaccard index among users’ connections, closeness centrality, and betweenness centrality, and (iii) by country and age information. Using the LFM-1b dataset of listening events of Last.fm users, we are able to uncover country-dependent differences in consumption of mainstream music as well as in user behavior with respect to social ties and users’ centrality. We could identify that users inclined to mainstream music tend to have stronger connections than the group of less mainstreamy users. Furthermore, our analysis revealed that users typically have less connections within a country than cross-country ones, with the first being stronger social ties, though. Results will help building better user models of listeners and in turn improve personalized music retrieval and recommendation algorithms

Measuring Commonality in Recommendation of Cultural Content: Recommender Systems to Enhance Cultural Citizenship

Recommender systems have become the dominant means of curating cultural content, significantly influencing the nature of individual cultural experience. While the majority of research on recommender systems optimizes for personalized user experience, this paradigm does not capture the ways that recommender systems impact cultural experience in the aggregate, across populations of users. Although existing novelty, diversity, and fairness studies probe how systems relate to the broader social role of cultural content, they do not adequately center culture as a core concept and challenge. In this work, we introduce commonality as a new measure that reflects the degree to which recommendations familiarize a given user population with specified categories of cultural content. Our proposed commonality metric responds to a set of arguments developed through an interdisciplinary dialogue between researchers in computer science and the social sciences and humanities. With reference to principles underpinning non-profit, public service media systems in democratic societies, we identify universality of address and content diversity in the service of strengthening cultural citizenship as particularly relevant goals for recommender systems delivering cultural content. Taking diversity in movie recommendation as a case study in enhancing pluralistic cultural experience, we empirically compare systems' performance using commonality and existing utility, diversity, and fairness metrics. Our results demonstrate that commonality captures a property of system behavior complementary to existing metrics and suggest the need for alternative, non-personalized interventions in recommender systems oriented to strengthening cultural citizenship across populations of users. In this way, commonality contributes to a growing body of scholarship developing 'public good' rationales for digital media and ML systems.Comment: The 16th ACM Conference on Recommender System