Diversity by Design in Music Recommender Systems

Lorenzo Porcaro,Carlos Castillo,Emilia Gómez

doi:10.5334/tismir.106

Abstract

Music Recommender Systems (Music RS) are nowadays pivotal in shaping the listening experience of people all around the world. Partly driven by the commercial application of this technology, music recommendation research has gained increasing attention both within and outside the Music Information Retrieval (MIR) community. Thanks also to the widespread use of recommender systems in music streaming services, it has been possible to enhance several characteristics of such systems in terms of performance, design, and user experience. Nonetheless, imagining Music RS only from an application-driven perspective may generate an incomplete view of how this technology is affecting people’s habitus, from the decision-making processes to the formation of musical taste and opinions. In this overview, we address the concept of diversity in music recommendation, and taking a value-driven approach we review diversity-related methodologies proposed in the Music RS literature. Additionally, by taking as an example the wider context of Information Technology (IT), we present the elements interacting in the diversity by design paradigm. We do that to acknowledge the lack of a comprehensive framework in Music RS research to address diversity, until now mostly driven by empirical results and fragmented in different application areas. Maintaining an interdisciplinary perspective, we discuss some challenges that MIR practitioners may face when researching Music RS, going beyond the search for better performance and instead questioning the theoretical foundations on which to base future research.

Highlights

Music, if conceived as a common heritage of humanity, is a heterogeneous mixture of creative processes taking shape in different historical, cultural, and societal contexts
We examine how diversity can be included in the design process of such technology in a principled and comprehensive manner (Friedman et Porcaro et al: Diversity by Design in Music Recommender Systems al., 2013), creating architectures which may help people in making diverse choices (Helberger, 2011), the idea defining the diversity by design approach
To imagine how diversity can be included as a design principle for the generation of Music RS is an open debate for the Music Information Retrieval (MIR) community, to which we aim to contribute with this overview

Summary

Introduction

If conceived as a common heritage of humanity, is a heterogeneous mixture of creative processes taking shape in different historical, cultural, and societal contexts. Balkanisation refers to the fragmentation of digital spaces into different communities based on their interests (Van Alstyne and Brynjolfsson, 2005) Under this lens, it is possible to identify the role that Music RS play in determining the exposure to music, and how most of the research until now has focused on empowering exposure diversity under an individual autonomy perspective (Helberger et al, 2018). Centered on the analysis of music lists (e.g. playlists, recommendation lists, sessions), where the user is often left aside (Table 3) Grouping users by their diversity is intended as grouping them by the diversity of the items they consumed, and in this behavioural perspective several important aspects related to the listener, the end-user of Music RS, are neglected as discussed . An important outcome of these studies is the differentiation between metric-based diversity, as measurement based on designed features extractable by algorithmic processes, and perceived diversity, how people evaluate a degree of diversity based on their personality, background, and beliefs (see Section 4.2)

Individual aspects

Collective aspects

Conclusions and Path Forward