Annual Report 2010 - Fachgruppe Informatik an der RWTH Aachen ...

Adaptive Multimodal Exploration of Music Collection
Dominik Lübbers
Current online music portals and systems for the management of private music collections
mainly concentrate on the support for directed search for music pieces (e.g. on the basis of
describing metadata like title, artist, etc.). However, empirical studies have shown that the
typical behaviour of customers in classic music retail stores is much more characterized by an
undirected browsing in the offered catalogue without being able to articulate a clear
information demand.
To improve support for this access paradigm, this thesis describes the conceptualization,
implementation and evaluation of a computer game-like exploration environment for music
collections, which allows its users to freely and autonomously explore a comprehensibly
structured music library.
Such a structure is based on a quantifiable notion of similarity between songs. Therefore, in
the first part of this thesis content-based, expert-based, collaborative and text-based
approaches for distance calculation are discussed and assessed. To model the multiple facets
of music similarity, a subset of these measures, which cover different aspects of music, are
combined into a summarizing distance function.
The generation of self-organizing maps allows the topology-preserving arrangement of pieces
on a two-dimensional map, on which similar songs are placed close to each other.
Furthermore, it allows the detection of cluster boundaries, that separate homogeneous groups
of similar pieces. This information can be used to build a three-dimensional virtual landscape,
which the user can freely navigate in.
A main contribution of this thesis is the supplementation of this visual presentation by
permanent spatialized acoustic playback of the placed pieces, which makes a media breakfree
communication of the actual exploration subject possible and thereby allows for a more
informed navigation of the user in the landscape. To prevent users' acoustic overstimulation
we developed and implemented concepts for perception focussing and intelligent selection of
songs for playback.
Besides the development of possibilities to customize the environment (e.g. by moving songs
or changing the height profile of the terrain), we also let the environment adapt to the user
automatically: On the basis of his interaction with the system, a re-weighting of the individual
similarity measure components is learned, which explains the structure provided by the user
best. The development of this adaptive distance measure which allows to model a
personalized similarity notion can be regarded as a further main contribution of this thesis.
A concluding evaluation shows the importance of the developed multimodal presentation for
the user's orientation in the virtual environment and proves the performance of the adaptive
distance function.
Evaluators: Prof. Dr. Matthias Jarke
Prof. Dr. Thomas Seidl
Date of oral exam: 8 December 2009
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