Visualizing Music Collections Based on Metadata: Concepts, User Studies and Design Implications

Modern digital music services and applications enable easy access to vast online and local music collections. To differentiate from their competitors, software developers should aim to design novel, interesting, entertaining, and easy-to-use user interfaces (UIs) and interaction methods for accessing the music collections. One potential approach is to replace or complement the textual lists with static, dynamic, adaptive, and/or interactive visualizations of selected musical attributes. A well-designed visualization has the potential to make interaction with a service or an application an entertaining and intuitive experience, and it can also improve the usability and efficiency of the system. This doctoral thesis belongs to the intersection of the fields of human-computer interaction (HCI), music information retrieval (MIR), and information visualization (Infovis). HCI studies the design, implementation and evaluation of interactive computing systems; MIR focuses on the different strategies for helping users seek music or music-related information; and Infovis studies the use of visual representations of abstract data to amplify cognition. The purpose of the thesis is to explore the feasibility of visualizing music collections based on three types of musical metadata: musical genre, tempo, and the release year of the music. More specifically, the research goal is to study which visual variables and structures are best suitable for representing the metadata, and how the visualizations can be used in the design of novel UIs for music player applications, including music recommendation systems. The research takes a user- centered and constructive design-science approach, and covers all the different aspects of interaction design: understanding the users, the prototype design, and the evaluation. The performance of the different visualizations from the user perspective was studied in a series of online surveys with 51-104 (mostly Finnish) participants. In addition to tempo and release year, five different visualization methods (colors, icons, fonts, emoticons and avatars) for representing musical genres were investigated. Based on the results, promising ways to represent tempo include the number of objects, shapes with a varying number of corners, and y-axis location combined with some other visual variable or clear labeling. Promising ways to represent the release year include lightness and the perceived location on the z- or x-axis. In the case of genres, the most successful method was the avatars, which used elements from the other methods and required the most screen estate. In the second part of the thesis, three interactive prototype applications (avatars, potentiometers and a virtual world) focusing on visualizing musical genres were designed and evaluated with 40-41 Finnish participants. While the concepts had great potential for complementing traditional text-based music applications, they were too simple and restricted to replace them in longer-term use. Especially the lack of textual search functionality was seen as a major shortcoming. Based on the results of the thesis, it is possible to design recognizable, acceptable, entertaining, and easy-to-use (especially genre) visualizations with certain limitations. Important factors include, e.g., the used metadata vocabulary (e.g., set of musical genres) and visual variables/structures; preferred music discovery mode; available screen estate; and the target culture of the visualizations

Novel music discovery concepts: user experience and design implications

Current music consumers are facing an almost endless selection of music in online services to be accessed on-demand with a variety of devices. The focus has now shifted from providing on-demand access to massive music catalogs towards improving the user experience of the music services, providing new ways of finding relevant music from the massive online catalogs, and making music consumption a pleasurable experience. The key differentiation aspects for music services come largely from the user interface and the ways that music can be found or consumed. This thesis belongs to the fields of human-computer interation (HCI) and music information retrieval (MIR). HCI is concerned with the design, evaluation and implementation of interactive computing systems and MIR targets to broaden the understanding and usage of musical data through research, applications and tools. This thesis studies novel concepts for music discovery that are based on strong visual metaphors and stereotypes. The goal is to research the user experience (UX) of novel music discovery services and to formulate key design implications to support service development for music discovery. The research of music discovery prototypes consisted of three main phases: initial concept design phase, playful concept exploration phase, and iterative concept design phase. The thesis introduces, in total, ten prototype implementations of these novel concepts for music discovery. User evaluations of the implemented prototypes were conducted with Finnish active music listeners with both qualitative and quantitative research methods. This thesis contributes to both academic research on HCI in MIR and commercial music discovery service development. The results provide insights to user experience with different types of novel music discovery services. Five novel music discovery services using the same content-based music recommendation back-end were compared and the comparison results are reported including both first impressions and longer-term usage. Additionally, the results of the studies introduce a wide set of future directions for each music discovery approach. These future directions enable service developers to further enhance the music discovery experience within these fields. All but one of the proposed music discovery concepts work well for music discovery. The use of avatar characters and mood pictures for music discovery are the most promising ones. The results show that visual music discovery services have the potential to replace traditional music discovery services in different types of music discovery practices. The final contribution of the thesis is a set of 16 design implications for music discovery service developers