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<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Using Personal Information Management Infrastructures to Facilitate User-Generated Services for Personal Use</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Olaf Grebner</string-name>
          <email>Olaf.Grebner@sap.com</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>SAP Research</institution>
          ,
          <addr-line>Vincenz-Priessnitz-Str. 1, 76131 Karlsruhe</addr-line>
          ,
          <country country="DE">Germany</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>Ad-hoc and situational applications for personal use will gain more and more traction in the work support for knowledge workers (KWers). Personal information is a key element in these applications. Composition environments for situational applications like, e.g., Yahoo Pipes, enable endusers to compose services into an application targeting their individual problems. However, we analyze that these composition environments lack access for a KWer's personal information and require redundant development of services for common KWer activities. Addressing these issues, we present 1an infrastructure that manages the KWer's personal information consistently and thus provides services that serve as basis for enabling end-user driven service composition for application for personal use. The infrastructure consists of two key components, a basic personal information management system to maintain a KWer's personal information cloud in a unified and integrated form and domain-specific services that offer business logic for frequently occurring activities in applications for a KWer's personal use.</p>
      </abstract>
      <kwd-group>
        <kwd>Olaf Grebner</kwd>
        <kwd>Service design</kwd>
        <kwd>User-centric software development</kwd>
        <kwd>Personal information management</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1 Introduction</title>
      <p>Ad-hoc and situational applications for personal use will gain more and more traction
in the work support for knowledge workers (KWers). The work conducted by
knowledge workers is characterized by variety rather than routine and there are few
activities that can be automated. Each KWer possesses an individual working style
and skill level making it hard to design applications that fit to a broad range of
KWers. Situational applications enable a KWer to adapt services to create
functionality and solve problems in their work. This allows the KWer to leverage an
individually created application tailored to the needs of that individual KWer for the
particular use case. The advantages of situational applications supporting a KWer are
manifold. On the one hand, the application fits to the KWer’s individual skill level,
targeting both novices and experts appropriately. On the other hand, KWers being
1 This work was has been partially funded by the European Commission as part of the</p>
      <p>NEPOMUK IP (Grant FP6-027705) and of the MATURE IP (Grant FP7-216346).
experts in their respective domain can come up with design ideas for solutions target
their individual problems of which they have a deep understanding.</p>
      <p>
        Personal information is a key element in applications for personal use. A KWer
deals with personal information in applications for personal use. A KWer’s personal
information refers to the information that is owned by an individual KWer. This
includes for example email messages in an email account or files on the computer’s
hard drive. A personal information cloud (PIC) is “the ‘working set’ of information
that is relevant to the individual and his work” [
        <xref ref-type="bibr" rid="ref10">Moran&amp;Zhai, 2007</xref>
        , p. 338], i.e., the
information an individual KWer manages for herself and deals with in the activities
she executes. The KWer regards the personal information as “one single body of
information” [
        <xref ref-type="bibr" rid="ref12">Ravasio&amp;Tscherter, 2007</xref>
        , p. 275], complementary to the personal
information cloud. "
        <xref ref-type="bibr" rid="ref13">Ravasio et al. (2004)</xref>
        indicate that users explicitly desire linking:
‘most interviewees expressed the need to have their information linked together, e.g.,
article author and respective address book entry, or citation and cited article, etc.’ (p.
169)" [
        <xref ref-type="bibr" rid="ref8">Jones&amp;Teevan, 2007</xref>
        , p. 143] [Ravasio et al., 2004].
      </p>
      <p>
        Composition environments for situational applications lack access for a KWer’s
personal information and require redundant development of services for common
KWer activities. Research fields such as end-user-development acknowledge the
importance of situational applications where individuals drive the creation of an
application to support their individual problems. On the web, mash-up services enable
an individual KWer to perform a specific form of end-user development already
today. Mash-up services like, e.g.,
        <xref ref-type="bibr" rid="ref16">Yahoo Pipes [Yahoo! Inc., 2009</xref>
        ] allow end-users
to create custom situational applications for a particular use case by visually
composing web-based services and designing corresponding user-interfaces.
However, these mentioned mash-up services lack two core elements when targeting
applications for personal use:
      </p>
      <p>Consistent access to a KWer’s personal information is not possible, as the KWer’s
personal information is scattered across multiple applications. This is a key
requirement as the KWer needs to have her personal information available during
work with these applications.</p>
      <p>High effort for developing applications in the personal domain due to a lack of
services that offer business logic for common, recurring activities in the KWer’s
personal domain, especially when dealing with personal information.</p>
      <p>
        Personal information management research started to integrate the KWer’s
personal information cloud into such composition environments, for example Konduit
[
        <xref ref-type="bibr" rid="ref3">Dragan et al., 2009</xref>
        ]. However, Konduit focuses solely on integrating desktop data
into the built applications, not tackling the problem of high development effort for
domain-specific components dealing with a KWer’s activities.
      </p>
      <p>The next section discusses in detail the respectively underlying problems of these
issues. These issues so far prevented the large-scale adoption of mash-up services for
personal use. To address these issues, we present an infrastructure that manages the
KWer’s personal information consistently and provides services that serve as basis for
enabling end-user driven service composition for application for personal use. The
infrastructure consists of two key components:
We leverage a basic personal information management system to maintain a
KWer’s personal information cloud in a unified and integrated form by using a
semantic desktop. Services can access all of the KWer’s personal information by
querying the personal information cloud’s consistent and integrated set of
information.</p>
      <p>We provide domain-specific services for composition that cover common business
logic which frequently occurs in applications for a KWer’s personal use. These
domain-specific services cover for example activities like task management or
meeting management. They enable the end-user to access and act on the personal
information and represent a basic infrastructure for the KWer’s personal domain in
end-user driven composition environments like the mentioned mash-up services.</p>
      <p>The here presented infrastructure offers service composition environments the
ability to access a KWer’s personal information in a consistent manner and thereby
offers re-usable services that match a KWer’s activities.</p>
      <p>The remaining paper is structured as follows: We first discuss the core problems
underlying for the identified issues of situational applications for personal use. This
includes on the one hand the personal information fragmentation in workspaces which
prevents efficient use of personal information as well as on the other hand that KWers
conduct a common set of supporting activities in their work which leads currently to
redundant implementations of supporting business logic. Then we propose a personal
information handling infrastructure that facilitates creating user-generated services for
personal use. It consists of the three elements of functionally-oriented applications,
domain-specific services and a basic personal information management (PIM) system.
We then discuss the benefits of this infrastructure and give a summary and an outlook.</p>
    </sec>
    <sec id="sec-2">
      <title>2 Core Problems of Situational Applications for Personal Use</title>
      <sec id="sec-2-1">
        <title>2.1 Personal Information Fragmentation in Workspaces Prevents Efficient Use of Personal Information</title>
        <p>
          The KWer’s personal information is fragmented across applications in digital
workspaces, i.e., the KWer’s personal information is scattered across the desktop and its
applications [
          <xref ref-type="bibr" rid="ref9">Jones, 2008</xref>
          ]. Current desktop systems and applications don't represent
the personal information cloud in a unified and integrated form as the KWer expects
it, i.e., the personal information is fragmented across applications in the workspace.
E.g., an email client folder containing emails has for the KWer no visible connection
to a file system folder containing documents despite dealing with the same topic.
        </p>
        <p>
          Workspace applications managing only a particular type of personal information
and locking it in a proprietary storage causes one major type of personal information
fragmentation. Karger mentions that these applications “often store their data in their
own particular locations and representations, inaccessible to other applications"
[
          <xref ref-type="bibr" rid="ref8">Jones&amp;Teevan, 2007</xref>
          , p. 127]. Karger outlines this type of information fragmentation as
paradox as this “information is fragmented by the very tools that have been designed
to help us manage it” [
          <xref ref-type="bibr" rid="ref8">Jones&amp;Teevan, 2007</xref>
          , p. 127]. Jones as well sees here "many
examples of seemingly avoidable information fragmentation" [
          <xref ref-type="bibr" rid="ref9">Jones, 2008</xref>
          , p. 392].
        </p>
        <p>
          Another related type of information fragmentation is produced by the KWer
herself. Due to application information silos, the KWer is forced to fragment the own
personal information when keeping it. This is due as each application only manages
particular own information types, i.e., information silos, regardless of the KWer's
intent for keeping the information. Bergmann reports this type of personal
information fragmentation problem in the context of organizing project-related
information, called project fragmentation problem [
          <xref ref-type="bibr" rid="ref2">Bergman et al., 2006</xref>
          ]. Figure 1
shows an example of "information related to a chemistry course" which is
"fragmented into separate collections" across three applications. The involved
applications' ability of managing each only a particular information element type
forces the KWer to organize the information in a fragmented way.
        </p>
      </sec>
      <sec id="sec-2-2">
        <title>2.2 KWer Conduct a Common Set Of Supporting Activities in Their Work</title>
        <p>
          The KWer performs activities in a personal value chain in analogy to an enterprise’s
value chain [
          <xref ref-type="bibr" rid="ref11">Porter, 1998</xref>
          ], see Figure 2. The KWer’s activities can be categorized
into the two types of personal primary activities and personal support activities.
        </p>
        <p>Personal primary activities are the working activities where the KWer actually
works towards achieving the individual goals. They depend largely on the KWer’s job
role and the KWer’s individual skills and capabilities. By executing personal primary
activities, the KWer produces the output that she gets rewarded for.</p>
        <p>Personal supporting activities enable the KWer to manage herself and things that
support her. They are independent of the KWer’s job role as they concern each
individual KWer. These supporting activities are cross cutting primary in the
execution through their support for primary activities. They as well vary in their
concrete instantiation from KWer to KWer depending on, e.g., the KWer’s job role,
gathered experience, felt importance and skill level. For example, KWers with a busy
schedule and workload feel a more urgent need to perform efficient task and time
management than KWers whose workday leaves sufficiently enough time to cope
with the workload. The following list covers the major supporting activities without
claiming to be exhaustive.</p>
        <p>Task Management (Task): Plan, structure and prioritize a set of tasks.
Time Management (Time): Plan and control available time.</p>
        <p>
          Personal Social Network Management (People): Build personal social network,
maintain the network and activate nodes within the network as needed
[
          <xref ref-type="bibr" rid="ref4">Fisher&amp;Nardi, 2007</xref>
          , p. 171].
        </p>
        <p>Meeting Management (Meeting): Prepare, conduct and post-process meetings.
Information Management (Information): Collect, organize, browse and retrieve
information.</p>
        <p>Collaboration Management (People, Information): Communicate and interact with
people.</p>
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        <sec id="sec-2-2-1">
          <title>Task Management (Task)</title>
          <p>lrtuppoS )(rtuppoS TPMiemeresetoiMnngaalnMSaaognceaimagleeNmnete(twTnitom(rMke)eMeatinnagg)ement (People)
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          <p>
            The KWer’s personal activities always include information processing activities.
Information processing activities include the KWer’s (re-)acquiring, processing,
organizing, and (re-)distributing of information [
            <xref ref-type="bibr" rid="ref9">Jones, 2008</xref>
            , p. 60]. The information
processing activities represent an orthogonal, information-centered perspective on the
activities that a KWer conducts, compared to this activity-centered perspective.
          </p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3 Personal Information Handling Infrastructure Facilitates</title>
    </sec>
    <sec id="sec-4">
      <title>Creating User-Generated Services for Personal Use</title>
      <p>
        We present an infrastructure that tackles the identified issues when developing
usergenerated applications for personal use. The proposed infrastructure consists of three
layers [
        <xref ref-type="bibr" rid="ref5">Grebner, 2009</xref>
        ]. Figure 3 shows on the left these layers from an end-user
perspective and shows on the right an architectural view on the same layers from an
application developer’s perspective. In the following we explain each layer in detail.
      </p>
      <p>TM Sidebar</p>
      <p>Email TM plug-in</p>
      <p>Domain-specific services
Application (end-user perspective)
Applications &amp; services</p>
      <p>Task …</p>
      <p>Management
Domain-specific services</p>
      <sec id="sec-4-1">
        <title>Email</title>
      </sec>
      <sec id="sec-4-2">
        <title>Website</title>
        <p>Personal information
?
User-generated
Meeting
Management</p>
      </sec>
      <sec id="sec-4-3">
        <title>Event</title>
      </sec>
      <sec id="sec-4-4">
        <title>Location</title>
      </sec>
      <sec id="sec-4-5">
        <title>Person</title>
      </sec>
      <sec id="sec-4-6">
        <title>Task</title>
      </sec>
      <sec id="sec-4-7">
        <title>Topic</title>
      </sec>
      <sec id="sec-4-8">
        <title>Document</title>
        <p>Service(functionalbuildingblock)
uses</p>
        <p>Architecture (application developer perspective)
User-generated Services &amp; Applications
TM
Application</p>
        <p>MM
Application
Task Management
Service
Meeting
Management Service
Data
alignment
PIM system</p>
        <p>Repository</p>
        <p>Data
wrapper
Desktop Operating System</p>
        <p>TM=Task Management,MM=Meeting Management</p>
        <sec id="sec-4-8-1">
          <title>3.1 Pre-built and User-Generated Applications for Personal Use</title>
          <p>
            First, facing the end-user, functionally-oriented applications each focus on supporting
a particular type of a KWer’s activity. Figure 3 shows two different user interfaces
targeting a KWer’s task management activities in different situations. On the one
hand, a task management (TM) sidebar [
            <xref ref-type="bibr" rid="ref6">Grebner et al., 2008</xref>
            ] shows the KWer’s tasks
and related information in a dedicated application focusing on task management. On
the other hand, an email TM plug-in enables the KWer to conduct task management
in the email client Microsoft Outlook while focusing on the tasks related to emails.
          </p>
          <p>
            These two vastly different applications base on the same information, i.e., a task
shown in one application can appear in the other application. Each application
represents a distinct perspective on the common underlying unified personal
information set. These applications can be implemented using multiple programming
languages and technologies. The two here presented applications have been built in
Java Swing and C#, respectively. Further applications for both the task management
and meeting management domain can be found in [
            <xref ref-type="bibr" rid="ref5">Grebner, 2009</xref>
            ].
          </p>
          <p>The vision fueled by the results of the here mentioned applications is that the
KWer can leverage composition environments for situational applications to create
user-generated applications for personal use. This happens by composing an
application that addresses the KWer’s individual activities and problems using the
offered domain-specific services, see the next section for details. For example, a
KWer composes a task management application following her own ideas on how to
conduct task management. By using the proposed infrastructure with domain-specific
services and the basic PIM system the task information produced by the composed
application can be integrated with the KWer’s personal information cloud and thus
neatly works with other existing applications of the KWer.</p>
        </sec>
        <sec id="sec-4-8-2">
          <title>3.2 Domain-Specific Services</title>
          <p>Second, a set of domain-specific services handles the access to a particular
perspective on a KWer’s personal information from the application layer to the
unified information model. The domain-specific service’s functionality provides the
needed parts of the personal information to domain-knowledgeable developers. This
way, the user experience of each application can be designed solely relying on the
domain and completely independent from the underlying (operating) system and
associated metaphors and paradigms. Domain-specific services provide controlling
business logic for applications on the application layer in the form of supporting
functionality and commonly handling the access to a corresponding perspective of the
KWer’s unified information model. We implemented domain-specific services
targeting the two personal supporting activities task management and meeting
management, see Figure 3.</p>
          <p>There are particular services for defined types of a KWer’s activities. The services
include functionality needed to support these activities. This includes, but is not
limited to, the management of a corresponding perspective on a KWer’s unified
personal information. Typically focusing on a major entity of the information model,
as for example tasks or people, the particular domain-specific service handles this
perspective and the major entities and contains business logic needed to process these
items. For example, for tasks there are service methods that create a new task, retrieve
tasks by different criteria or methods to delegate a task.</p>
          <p>The domain-specific service encapsulates the domain-specific business logic in a
way that domain-knowledgeable KWers can apply these services without being
experts in personal information management. As this domain-specific business logic
is encapsulated in a service it can be re-used at every workspace or workspace-level
application that needs to access an entity of the information model.</p>
          <p>
            On the implementation side of the domain-specific services, their business logic
interfaces core services provided by the basic PIM system such as, e.g., storage and
communication. The domain-specific services’ business logic interfaces the basic
PIM system by invoking its services like, e.g., a PIM service to read and write the
unified information model and a data wrapper for handling desktop information
elements like files and emails. In our implementation with the Nepomuk semantic
desktop as basic PIM system, they interface the core system services like for example
PimoService [
            <xref ref-type="bibr" rid="ref14">Sauermann&amp;Klinkigt, 2009</xref>
            ] to read and write the unified personal
information model and the Aperture DataWrapper [
            <xref ref-type="bibr" rid="ref1">Aduna B.V.&amp;DFKI GmbH, 2005</xref>
            ]
as indexer for desktop information elements like files and emails.
          </p>
        </sec>
        <sec id="sec-4-8-3">
          <title>3.3 Basic PIM System</title>
          <p>
            Third, using a basic PIM system we can access numerous desktop services and thus
re-use desktop functionality without replicating it in each workspace. Here we use the
semantic desktop Nepomuk [
            <xref ref-type="bibr" rid="ref7">Groza et al., 2007</xref>
            ] as example for a service-oriented
basic PIM system. The Nepomuk semantic desktop provides a service-oriented
desktop architecture and services. The basic PIM system manages the unified
personal information model representing the KWer’s personal information cloud and
offers a PIM Service providing generic read and write functionality for the unified
personal information model. Nevertheless, it is user-owned but formally represented
using a set of ontologies. We use a formalized representation of this model, the
Personal Information Model Ontology (PIMO) [
            <xref ref-type="bibr" rid="ref15">Sauermann et al., 2007</xref>
            ] to enable
machine processing on it by the domain-specific services. It features a unified
representation through the RDF representation and it is integrated along the KWer’s
personal things. This represents the KWer’s mental model, i.e., the personal,
subjective view on the world. Furthermore, it encapsulates core operating
functionality in services like, e.g., handling desktop information objects like for
example, emails, websites and files.
          </p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>4 Discussion of Benefits</title>
      <p>Through using the proposed infrastructure, developers and end-users in a role to
compose an application gain a number of benefits. First, it significantly reduces the
complexity of implementing applications.</p>
      <p>Offering a domain-specific interface reduces the complexity to build an application
by opening the development of personal activity support applications to
domainknowledgeable developers while omitting the need for deep personal information
management expertise. The domain-specific interface of the domain-specific services
allows domain-knowledgeable developers to efficiently handle unified personal
information. A domain-specific interface hides the underlying personal information
management technology details. In comparison to a generic personal information
management interface this saves domain-knowledgeable developers getting into the
internals of personal information management and related technology.</p>
      <p>A common PIM system infrastructure reduces the complexity to build a personal
activity support applications by replacing the need for applications and the
domainspecific services to each redundantly implement a proprietary stack for integrating
desktop information objects. The common PIM system infrastructure underlies the
applications and the domain-specific services. The PIM system, i.e., the semantic
desktop, provides services and models to manage existing desktop information
elements and to integrate them with the unified information model. This means that
the PIM system infrastructure is re-usable instead of each application building an own
management stack. This replaces the need for applications and the domain-specific
services to each redundantly implement a proprietary stack for integrating desktop
information objects, significantly reducing the complexity of implementing
applications.</p>
      <p>Second, using this reference architecture significantly improves the capabilities
that developers can implement into personal activity support applications.</p>
      <p>An increased flexibility for building applications can be realized as existing
business logic for certain KWer activities can be re-used and only the user interface
needs to be re-developed and designed, for example using the described composition
environments for situational applications. The domain-specific services provide a
number of services to realize the functionality needed for supporting a KWer’s
activities like, e.g., task delegation to send off a task to other people. As long as these
services are available, developers can quicker develop new applications featuring an
improved user interaction compared to when they need to re-develop the full personal
information management stack. The service-oriented desktop architecture of the
Nepomuk semantic desktop PIM system facilitates this re-use further as it keeps the
available services in a service registry allowing other applications to discover and use
these services. This enables multiple applications that are implemented in different
programming languages to invoke the provided services. By invoking services,
multiple applications can, e.g., query and write to the common unified personal
information model.</p>
    </sec>
    <sec id="sec-6">
      <title>5 Summary and Outlook</title>
      <p>To summarize, the here presented infrastructure offers service composition
environments the ability to access a KWer’s personal information in a consistent
manner and thereby offers re-usable services that match a KWer’s activities on a
domain-specific level. This enables KWers to compose applications and services for
personal use. Alternatively, it as well eases the work of developers developing
respective components. At hand of task and meeting management services and two
example applications we showed how tailored application “hats” can re-use common
business logic to offer services and applications in the KWer’s personal support
domain.</p>
      <p>Due to the service-based nature of this infrastructure, we want to enable service
composition environments to consume the domain-specific services and thus offer
application support for the personal use domain of KWers. The here presented
principle of a personal information cloud and domain-specific services has been
implemented for personal information on the desktop. The KWer’s personal
information is thus securely stored in an information repository that is accessible only
to the one individual KWer owning it. To enable these services for use by the
mentioned service composition environments, the KWer’s personal information
cloud, the used basic PIM system and the domain-specific services will be ported into
web-based services and a multi-user environment while maintaining the privacy of the
KWer’s personal information cloud. In addition, the next implementation version will
incorporate as well personal information already managed by web-based services,
such as for example social networks, online storage providers as well as online email
providers.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          <string-name>
            <surname>Aduna</surname>
            <given-names>B.V.</given-names>
          </string-name>
          ; DFKI GmbH (
          <year>2005</year>
          ). Aperture. http://aperture.sourceforge.net.
          <source>Accessed</source>
          <year>2009</year>
          .
          <volume>10</volume>
          .31.
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          <string-name>
            <surname>Bergman</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Beyth-Marom</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Nachmias</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          (
          <year>2006</year>
          ).
          <article-title>The project fragmentation problem in personal information management</article-title>
          .
          <source>CHI '06: Proceedings of the SIGCHI conference on Human Factors in computing systems</source>
          (p.
          <fpage>271</fpage>
          -
          <lpage>274</lpage>
          ). New York, NY, USA: ACM.
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          <string-name>
            <surname>Dragan</surname>
            ,
            <given-names>L.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Möller</surname>
            ,
            <given-names>K.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Handschuh</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Ambrus</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Trüg</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          (
          <year>2009</year>
          ).
          <article-title>Converging Web and Desktop Data with Konduit</article-title>
          .
          <source>Proc. of Scripting and Development for the Semantic Web Workshop</source>
          . http://CEUR-WS.org/Vol-
          <volume>449</volume>
          /Paper4.pdf.
          <source>Accessed</source>
          <year>2009</year>
          .
          <volume>10</volume>
          .31.
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          <string-name>
            <surname>Fisher</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Nardi</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          (
          <year>2007</year>
          ).
          <article-title>Soylent and ContactMap: Tools for Constructing the Social Workscape</article-title>
          . In V. Kaptelinin &amp;
          <string-name>
            <surname>M. Czerwinski</surname>
          </string-name>
          (Eds.),
          <article-title>Beyond the desktop metaphor: designing integrated digital work environments</article-title>
          (p.
          <fpage>171</fpage>
          -
          <lpage>190</lpage>
          ). MIT Press, Cambridge, Mass.
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          <string-name>
            <surname>Grebner</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          (
          <year>2009</year>
          ).
          <article-title>Using Unified Personal Information in Workspaces</article-title>
          .
          <source>PhD thesis</source>
          . http://digbib.ubka.uni-karlsruhe.de/volltexte/1000012169. Accessed
          <year>2009</year>
          .
          <volume>10</volume>
          .31.
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          <string-name>
            <surname>Grebner</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Ong</surname>
            ,
            <given-names>E.</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Riss</surname>
            ,
            <given-names>U.</given-names>
          </string-name>
          (
          <year>2008</year>
          ).
          <article-title>KASIMIR - Work process embedded task management leveraging the Semantic Desktop</article-title>
          . In M. Bichler,
          <string-name>
            <given-names>T.</given-names>
            <surname>Hess</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H.</given-names>
            <surname>Krcmar</surname>
          </string-name>
          ,
          <string-name>
            <given-names>U. L. F.</given-names>
            <surname>Matthes</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Picot</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Speitkamp</surname>
          </string-name>
          &amp; P. Wolf (Eds.), Multikonferenz Wirtschaftsinformatik (p.
          <fpage>715</fpage>
          -
          <lpage>726</lpage>
          ). GITO-Verlag, Berlin.
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          <string-name>
            <surname>Groza</surname>
            ,
            <given-names>T.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Handschuh</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Moeller</surname>
            ,
            <given-names>K.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Grimnes</surname>
            ,
            <given-names>G.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Sauermann</surname>
            ,
            <given-names>L.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Minack</surname>
            ,
            <given-names>E.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Mesnage</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Jazayeri</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Reif</surname>
            ,
            <given-names>G.</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Gudjonsdottir</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          (
          <year>2007</year>
          ).
          <article-title>The Nepomuk project-on the way to the social semantic desktop</article-title>
          .
          <source>Proceedings of I-Semantics</source>
          (Vol.7,
          <string-name>
            <surname>S.</surname>
          </string-name>
          201-
          <fpage>211</fpage>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          <string-name>
            <surname>Jones</surname>
            ,
            <given-names>W.</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Teevan</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          (
          <year>2007</year>
          ). Personal Information Management University of Washington Press.
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          <string-name>
            <surname>Jones</surname>
            ,
            <given-names>W.</given-names>
          </string-name>
          (
          <year>2008</year>
          ).
          <article-title>Keeping Found Things Found Elsevier Inc</article-title>
          .
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          <string-name>
            <surname>Moran</surname>
            ,
            <given-names>T. P.</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Zhai</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          (
          <year>2007</year>
          ).
          <article-title>Beyond the Desktop Metaphor in Seven Dimensions</article-title>
          . In V. Kaptelinin &amp;
          <string-name>
            <surname>M. Czerwinski</surname>
          </string-name>
          (Eds.),
          <article-title>Beyond the desktop metaphor: designing integrated digital work environments</article-title>
          (p.
          <fpage>335</fpage>
          -
          <lpage>354</lpage>
          ). MIT Press, Cambridge, Mass.
        </mixed-citation>
      </ref>
      <ref id="ref11">
        <mixed-citation>
          <string-name>
            <surname>Porter</surname>
            ,
            <given-names>M. E.</given-names>
          </string-name>
          (
          <year>1998</year>
          ).
          <article-title>Competitive advantage: Creating and sustaining superior performance Free Press</article-title>
          .
        </mixed-citation>
      </ref>
      <ref id="ref12">
        <mixed-citation>
          <string-name>
            <surname>Ravasio</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Tscherter</surname>
            ,
            <given-names>V.</given-names>
          </string-name>
          (
          <year>2007</year>
          ).
          <article-title>Users' Theories of the Desktop Metaphor, or Why We Should Seek Metaphor-Free Interfaces</article-title>
          . In V. Kaptelinin &amp;
          <string-name>
            <surname>M. Czerwinski</surname>
          </string-name>
          (Eds.),
          <article-title>Beyond the desktop metaphor: designing integrated digital work environments</article-title>
          (p.
          <fpage>265</fpage>
          -
          <lpage>294</lpage>
          ). MIT Press, Cambridge, Mass.
        </mixed-citation>
      </ref>
      <ref id="ref13">
        <mixed-citation>
          <string-name>
            <surname>Ravasio</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Schär</surname>
            ,
            <given-names>S. G.</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Krueger</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          (
          <year>2004</year>
          ).
          <article-title>In pursuit of desktop evolution: User problems and practices with modern desktop systems</article-title>
          .
          <source>ACM Trans. Comput</source>
          .-Hum. Interact.,
          <volume>11</volume>
          (
          <issue>2</issue>
          ),
          <fpage>156</fpage>
          -
          <lpage>180</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref14">
        <mixed-citation>
          <string-name>
            <surname>Sauermann</surname>
            ,
            <given-names>L.</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Klinkigt</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          (
          <year>2009</year>
          ). PIMO Service. http://dev.nepomuk.semanticdesktop.org/wiki/PimoService. Accessed
          <year>2009</year>
          .
          <volume>10</volume>
          .31.
        </mixed-citation>
      </ref>
      <ref id="ref15">
        <mixed-citation>
          <string-name>
            <surname>Sauermann</surname>
            ,
            <given-names>L.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Van Elst</surname>
            ,
            <given-names>L.</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Dengel</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          (
          <year>2007</year>
          ).
          <article-title>Pimo-a framework for representing personal information models</article-title>
          .
          <source>Proceedings of I-Semantics</source>
          (p.
          <fpage>270</fpage>
          -
          <lpage>277</lpage>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref16">
        <mixed-citation>
          <string-name>
            <surname>Yahoo</surname>
          </string-name>
          ! Inc. (
          <year>2009</year>
          ). Yahoo Pipes. http://pipes.yahoo.com/pipes/.
          <source>Accessed</source>
          <year>2009</year>
          .
          <volume>10</volume>
          .31.
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>