Quality of Context: First International Workshop, QuaCon 2009, Stuttgart, Germany, June 25-26, 2009. Revised Papers.

193 Pages·2009·4.656 MB·English

by  Max Mühlhäuser, Melanie Hartmann (auth.), Kurt Rothermel, Dieter Fritsch, Wolfgang Blochinger, Frank Dürr (eds.)

Lecture Notes in Computer Science 5786
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Kurt Rothermel Dieter Fritsch
Wolfgang Blochinger Frank Dürr (Eds.)
Quality of Context
First International Workshop, QuaCon 2009
Stuttgart, Germany, June 25-26, 2009
Revised Papers
1 3
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KurtRothermel
WolfgangBlochinger
FrankDürr
InstituteofParallelandDistributedSystems(IPVS),UniversityofStuttgart
Universitätsstr.38,70569Stuttgart,Germany
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DieterFritsch
InstituteforPhotogrammetry,UniversityofStuttgart
Geschwister-Scholl-Str.24D,70174Stuttgart,Germany
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Preface
Advancesinsensortechnology,wirelesscommunication,andmobiledeviceslead
to the proliferation of sensors in our physical environment. At the same time
detailed digital models of buildings, towns, or even the globe become widely
available.Integratingthe hugeamountofsensordataintospatialmodelsresults
in highly dynamic models of the real world, often called context models.
A wide range of applications can substantially benefit from context models.
However, context data are inherently associated with uncertainty. In general,
quality of context information has to be taken into account by both context
management and applications. For example, the accuracy, completeness, and
trustworthiness of spatial context information such as street or building data
are very important for navigation and guidance systems.
QuaCon 2009 was the first international scientific meeting that specifically
focused on the different aspects of quality of context data. Research in context
management and, in particular, context quality, requires an interdisciplinary
approach.Therefore,the QuaConworkshopaimedto bringtogetherresearchers
fromvariousfieldstodiscussapproachestocontextqualityandtomakeaconsol-
idatedcontributiontowardanintegratedwayoftreatingthis topic.We received
19 high-quality paper submissions by researchers from Europe, USA, and Asia.
TheInternationalProgramCommitteeselected11papersforpresentationatthe
workshop. Additionally, five invited contributions by internationally renowned
expertsinthefieldwereincludedintheworkshopprogram.Thepresentationsat
the workshop showed many facets of quality of context from different research
fields including context data management, spatial models, context reasoning,
privacy, and system frameworks. The lively discussions underlined the great in-
terestinthistopicandinparticularledtoadeeperunderstandingoftherelations
between the various aspects of quality of context.
The success of QuaCon2009 was the result of a team effort. We are grateful
to the members of the ProgramCommittee and the external reviewers for their
thorough and timely reviews as well as to the authors for their high-quality
submissionsandinterestingtalks.We wouldliketoextendspecialthanksto our
invited speakers for their excellent and inspiring keynotes. Finally, we wish to
thank all persons involved in the organization of the QuaCon 2009 workshop
who did really a great job.
July 2009 Kurt Rothermel
Dieter Fritsch
ProgramChairs
QuaCon 2009
Organization
QuaCon 2009 was organized by the Collaborative Research Center 627 “Spa-
tial World Models for Mobile Context-Aware Applications” at the University of
Stuttgart, Germany.
Executive Committee
ProgramChairs Kurt Rothermel and Dieter Fritsch
Organizing Chairs Frank Du¨rr and Wolfgang Blochinger
Local Arrangements Chair Michael Matthiesen
Financial Chair Michael Matthiesen
Proceedings Chair Wolfgang Blochinger
Demonstrations Chair Frank Du¨rr
Program Committee
Reynold Cheng University of Hong Kong, SAR China
Alois Ferscha University of Linz, Austria
Andrew U. Frank Technical University of Vienna, Austria
Christian Freksa University of Bremen, Germany
Johann-Christoph Freytag Humboldt-Universita¨t zu Berlin, Germany
Dieter Fritsch Universita¨t Stuttgart, Germany
Hans Gellersen University of Lancaster, UK
Christopher Gold University of Glamorgan, UK
Michael F. Goodchild University of California, Santa Barbara,USA
Christian S. Jensen Aalborg University, Denmark
Bernhard Mitschang Universita¨t Stuttgart, Germany
Max Mu¨hlha¨user Technical University Darmstadt, Germany
Paddy Nixon University College Dublin, Ireland
Sunil K. Prabhakar Purdue University, USA
Kishore Ramachandran Georgia Institute of Technology, USA
Kurt Rothermel Universita¨t Stuttgart, Germany
External Referees
N. Ahmed M. Kost L. Sun
A. Avanes R. Lange H. Weinschrott
M. Bhatt K. Richter D. Wolter
J. Chen S. Rizou L. Yusuf
L. Geiger J. Shin Y. Zhang
VIII Organization
Sponsoring Institutions
Gesellschaft fu¨r Informatik (GI) e.V.
Informatik-Forum Stuttgart (infos) e.V.
Invited Speakers
Max Mu¨hlha¨user, Technical University Darmstadt, Germany
Michael F. Goodchild, University of California, Santa Barbara,USA
Johann-Christoph Freytag, Humboldt-Universita¨t zu Berlin, Germany
Reynold Cheng, University of Hong Kong, SAR China
Christopher Gold, University of Glamorgan, UK
Table of Contents
Invited Papers
Interacting with Context.......................................... 1
Max Mu¨hlha¨user and Melanie Hartmann
The Quality of Geospatial Context ................................. 15
Michael F. Goodchild
Context Quality and Privacy - Friends or Rivals? .................... 25
Johann-Christoph Freytag
Querying and Cleaning Uncertain Data ............................. 41
Reynold Cheng
Spatial Embedding and Spatial Context ............................ 53
Christopher Gold
Contributed Papers
A Context Quality Model to Support Transparent Reasoning with
Uncertain Context ............................................... 65
Susan McKeever, Juan Ye, Lorcan Coyle, and Simon Dobson
On a Generic Uncertainty Model for Position Information............. 76
Ralph Lange, Harald Weinschrott, Lars Geiger, Andr´e Blessing,
Frank Du¨rr, Kurt Rothermel, and Hinrich Schu¨tze
A Probabilistic Filter Protocolfor Continuous Queries................ 88
Jinchuan Chen, Reynold Cheng, Yinuo Zhang, and Jian Jin
Establishing Similarity across Multi-granular Topological–Relation
Ontologies ...................................................... 98
Matthew P. Dube and Max J. Egenhofer
UDS:SustainingQualityofContextUsingUninterruptibleDataSupply
System ......................................................... 109
Naoya Namatame, Jin Nakazawa, Kazunori Takashio, and
Hideyuki Tokuda
A Framework for Quality of Context Management.................... 120
Zied Abid, Sophie Chabridon, and Denis Conan
An Abstract Processing Model for the Quality of Context Data ........ 132
Matthias Grossmann, Nicola Ho¨nle, Carlos Lu¨bbe, and
Harald Weinschrott
X Table of Contents
Using Quality of Context to Resolve Conflicts in Context-Aware
Systems ........................................................ 144
Atif Manzoor, Hong-Linh Truong, and Schahram Dustdar
Presentationand Evaluation of Inconsistencies in Multiply Represented
3D Building Models .............................................. 156
Michael Peter
BringingQualityofContextintoWearableHumanActivityRecognition
Systems ........................................................ 164
Claudia Villalonga, Daniel Roggen, Clemens Lombriser,
Piero Zappi, and Gerhard Tro¨ster
Quality Dependent Reconstruction of Building Fac¸ades ............... 174
Susanne Becker and Norbert Haala
Author Index.................................................. 185
Interacting with Context
Max Mühlhäuser and Melanie Hartmann
Technische Universität Darmstadt, Telecooperation Lab,
Hochschulstr. 10,
64289 Darmstadt, Germany
{max,melanie}@tk.informatik.tu-darmstadt.de
Abstract. Context is dodgy - just as the human computer user: hard to predict,
erroneous, and probabilistic in nature. Linking the two together i.e. creating
context-aware user interfaces (UIs) remains a great challenge in computer sci-
ence since ubiquitous computing calls for lean, situated, and focused UIs that
can be operated on the move or intertwined with primary tasks grabbing the us-
er's attention. The paper reviews major categories of context that matter at the
seam of humans and computers, emphasizing quality issues. Approaches to the
marriage of context-awareness and user modeling are highlighted, including our
own approach. Both sides of the coin are inspected: the improvement of UIs by
means of quality attributed context information and, to a lesser extent, the chal-
lenge to convey context quality to the user as part of the interaction.
Keywords: Context-Aware Computing, Intelligent User Interfaces.
1 Introduction
Fifteen years after its advent, the term context-aware computing – and hence, the
concept of context as used therein – remains a subject of definition quarrels. In the
present paper, we apply an understanding that mediates between common usages of
the term in the research literature (what kinds of systems and applications are called
context-aware?) and etymological considerations (what would humans consider a
correct use of the term ‘context’ in the light of its linguistic roots?). These considera-
tions lead to the following definition:
Context in the sense of context-aware computing is
─ auxiliary information1 (in the sense of ‘input’), used to improve the behavior of
computer based systems (system or application software, appliances), whereby
─ ‘improved behavior’ relates to the functionality itself or to the user interface
─ and either physical conditions in which the software or system is operated
─ or human factors related to the actual user(s)2 are taken into account,
─ both being predominantly probabilistic and time-dependent in nature

1 This definition is at odds with, e.g., [28]. It excludes systems like navigation aids that require
location as input yet reflects the meaning of ‘in the context of’ as ‘in conjunction with’.
2 Physical conditions and human factors as context were first distinguished in [29].
K. Rothermel et al. (Eds.): QuaCon 2009, LNCS 5786, pp. 1–14, 2009.
© Springer-Verlag Berlin Heidelberg 2009
2 M. Mühlhäuser and M. Hartmann
The QuaCon workshop rightly emphasizes the probabilistic nature of context, calling
for approaches to the formalization and systematic consideration of this nature – and
hence for elaborate concepts that cope with context quality. As to the second line item
in the above context definition, the present paper is restricted to the role of context at
the user interface. The paper title ‘interacting with context’ is deliberately ambiguous:
both ‘context-aware interaction’ and ‘user interfaces for conveying context informa-
tion’ shall be addressed in the remainder. Given these introductory remarks, the topic
of the present paper can be formulated and structured as follows:

Interacting with context concerns
i) improvement of UIs based on context, including
quality (of context) considerations
ii) interaction regarding context and its quality

The italicized words in the above statement are used to devise the core structure of
the paper. Chapter 2 addresses improvements i.e. ways to optimize UIs based on
context. Chapter 3 deals with context proper: it discusses important categories and
characteristics of context. Chapter 4 reviews quality ‘types’ and aspects of context,
followed by approaches to the consideration of this quality in chapter 5, extending UI
improvement as described in chapter 2. Chapter 6 turns to the second interpretation of
‘interacting with context’, with a particular emphasis on how to communicate about
and how to present the quality of given context information at the UI.
The aforementioned chapters concern the state of the art in general. Chapter 7 takes
a look at specific approaches for interacting with context developed by the authors
and their colleagues at our Lab, followed by conclusions and outlook in chapter 8.
2 Possible User Interface Improvements
We have to refine the distinction between system functionality and UI made in the
above definition; as mentioned before, this paper focuses on the latter. Recent devel-
opments lead to the inclusion of context-aware information retrieval and information
filtering (IR/IF) [1] in these UI considerations. At first sight, IR/IF is just an applica-
tion domain, suggesting that context-aware IR/IF should just be subsumed under
‘functionality’. However, as we can observe in our daily Web and desktop activities,
IR/IF has become an integral part of most of our computer usages, tightly related to
the ‘how’ and ‘what’ of UI usage (determination of parameters etc.). Therefore we
split ‘context-aware UI improvement’ into context-aware information handling (in the
general meaning of IR/IF) and context-aware system use, respectively. (Readers more
interested in the functionality aspect of context-aware IR/IF may refer to [1].)

A. Information handling: with respect to IR/IF, context-awareness improves the
information conveyed to the user. Three possibilities can be distinguished:
1. Direct presentation: context information proper is conveyed to the user; an exam-
ple is the ContextPhone [2], which displays additional context information about a
user, e.g. her current location, phone use activity, nearby acquaintances, etc.