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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>The Four Elements of a viable PLE</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Sandy El Helou</string-name>
          <email>sandy.elhelou@epfl.ch</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Denis Gillet</string-name>
          <email>denis.gillet@epfl.ch</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Swiss Federal Institute of Technology in Lausanne, (EPFL)</institution>
          ,
          <addr-line>1015 Lausanne</addr-line>
          ,
          <country country="CH">Switzerland</country>
        </aff>
      </contrib-group>
      <fpage>30</fpage>
      <lpage>33</lpage>
      <abstract>
        <p>In this paper, we propose and discuss four fitness features considered as essential for developing personal learning environments (PLE) that are viable and ready for appropriation.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Personal Learning Environments</kwd>
        <kwd>lifelong learning</kwd>
        <kwd>knowledge management</kwd>
        <kwd>social media</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. INTRODUCTION</title>
      <p>
        Rather than being confined to earlier life stages and strictly
acquired within standard educational systems, learning should
be actively pursued during the lifetime period. “Lifelong,
lifewide, voluntary, and self-motivated” learning [1] refers to the
activities that people conduct during their lifetime, to develop
knowledge and competences, motivated by personal, social as
well as employment reasons [2,3]. Lifelong learning is about
learning anything, anywhere, anytime and anyway. It
encompasses formal, non-formal and informal learning. Formal
learning refers to intentional learning that occurs in structured
contexts, and often leads to a formal recognition (e.g. diploma,
certificate). Non-formal and informal learning, on the other
hand, take place in environments that are neither essentially
learning-oriented, nor structured in terms of learning objectives,
material, time, or support [4]. Different from non-formal
learning, informal learning is accidental or spontaneous, and
occurs over the lifetime period [
        <xref ref-type="bibr" rid="ref1">5,6</xref>
        ].
      </p>
      <p>Traditional LMS (Learning Management Systems) are not
suitable for lifelong learning. LMS systems are usually
characterized by a hardcoded asymmetry in user rights [7].
Students usually have single predetermined roles, share the same
homogenous learning context, and are expected to achieve the
same learning goals within the same period. Moreover, learning
content is pre-packaged in learning units, has a restricted
visibility scope (usually limited to the course duration), and is
isolated from the outside world. Sometimes, courses cannot even
be shared within the same LMS.</p>
      <p>
        To better address the requirements of lifelong learning,
educational systems need to become part of an external system
accounting for learning inside and outside formal academic
environments [
        <xref ref-type="bibr" rid="ref4">8</xref>
        ]. There is a need to shift from traditional LMS
applications particularly focused on formal interactions and
learning, to online personal learning environments (PLE)
supporting both institutional and self-directed, intended and
accidental learning. Successfully sustaining lifelong learning
with online PLE requires developing and adopting new design
patterns, models, and prototypes that can substitute for prevalent
LMS design patterns [
        <xref ref-type="bibr" rid="ref5">9</xref>
        ]. In this paper, we discuss four elements
deemed important for ensuring an online PLE’s fitness for
adoption and lifelong survival.
      </p>
    </sec>
    <sec id="sec-2">
      <title>2. THE FOUR PLE ELEMENTS</title>
      <p>
        This paper is based on the following definition of online PLEs:
online PLEs are environments that are built from the perspective
of the individual rather than the institution [
        <xref ref-type="bibr" rid="ref6">10</xref>
        ] and give learners
the opportunity to decide their own learning goals, control their
learning spaces [
        <xref ref-type="bibr" rid="ref7">11</xref>
        ] and interact with each other during the
learning process [
        <xref ref-type="bibr" rid="ref8">12</xref>
        ]. The four identified features for building
successful PLE are described below.
      </p>
    </sec>
    <sec id="sec-3">
      <title>2.1 Encouraging active participation by adopting social media paradigms</title>
      <p>
        The problem of low participation and lack of personal incentives
was a major issue in early collaborative applications [
        <xref ref-type="bibr" rid="ref9">13</xref>
        ]. By
adopting a user-centered bottom-up philosophy and relying on
Web 2.0 technologies, social media applications have
successfully overcome several problems identified by earlier
CSCW studies, achieving by that a higher acceptability and a
better user experience than traditional groupware. Online PLE
should embrace the social media practices of knowledge
“democratization” encouraging active participation and
facilitating information dissemination as well as social
interactions.
      </p>
      <p>
        First, having low learning curves and offering interactive
user-friendly interfaces is crucial for achieving fitness. With
respect to developing interactive interfaces and improving the
user experience, Web 2.0 technologies such as AJAX1 play a
particularly important role if applied properly [
        <xref ref-type="bibr" rid="ref10">14</xref>
        ].
      </p>
      <p>
        Second, PLE should encourage learner-generated content by
providing easy individual and collaborative authoring features
such as blogs and wikis. Learner-generated metadata can be
achieved by offering social tagging. The term folksonomy
denotes the Web 2.0 way of organizing content using tags
created and shared by people [
        <xref ref-type="bibr" rid="ref11">15</xref>
        ].
      </p>
      <p>
        Third, PLE should combine content management facilities with
social networking features allowing people to explicitly build
and publish their own network of connections. People achieve
lifelong learning by creating, maintaining, extending and
strengthening their personal network composed of people with
similar interest, groups, systems and specialized information sets
[
        <xref ref-type="bibr" rid="ref12">16</xref>
        ].
      </p>
      <p>
        Fourth, PLE should incorporate SALT features. SALT (Share,
Assess, Link, Tag) is an acronym introduced in [
        <xref ref-type="bibr" rid="ref13">17</xref>
        ] to account
for social media features that facilitate information
dissemination and trigger interactions and reflection on
knowledge artefacts. Assessment includes liking/disliking,
commenting, and rating. Giving users the opportunity to easily
contribute and express their views leads to a better appropriation
of the online platform and increases their motivation to
collaborate with others. Creating links (or bookmarks) to people
and content and sharing them allows discovering the
connections between different items, and discovering new items
through their connections with known ones. Tagging can be
used for describing an item or categorizing it using a
user-defined label. Additionally, using tag-based search and tag
clouds, learners can discover communities, activities, and
artefacts that are relevant to specific topics of interest. Tagging
people have also proven to be useful in formal contexts [
        <xref ref-type="bibr" rid="ref14">18</xref>
        ].
Influenced by users’ tagging practices in collaborative tagging
systems, tag semantics can emerge and evolve [
        <xref ref-type="bibr" rid="ref15">19</xref>
        ]. This helps
communities to incrementally build a common vocabulary and
externalize their shared memory. A direct advantage of
incorporating these social media features is generating
unobtrusive relation-based recommendations whereby metadata
resulting from SALT actions are exploited in order to bring to the
surface relevant people, activities, and knowledge artefacts
based on how and by whom they have been “salted”.
      </p>
    </sec>
    <sec id="sec-4">
      <title>2.2 Representing interaction and learning contexts in a flexible way</title>
      <p>
        Ackerman identifies the necessity of providing flexible, nuanced
and contextualized CSCW (Computer-Supported Collaborative
Work) apparatus just as human behavior is “flexible, nuanced
and contextualized” [20]. This statement perfectly applies to
PLE that should be designed in a flexible and bottom-up way
and account for heterogeneous interaction and learning
contexts, including work, formal learning, and even play [
        <xref ref-type="bibr" rid="ref16">21</xref>
        ].
Learners should be given the opportunity to design and manage
their own learning “contexts” by mashing up application
widgets and useful artefacts, then sharing them with different
1AJAX (Asynchronous JavaScript and XML) combined
technologies exchange data asynchronously with the server to
respond to a user’s request. This avoids freezing the current
people in different contexts. At the same time, it should not be
imposed on learners to explicitly specify their interaction and
learning contexts. PLE should allow different ways of context
identification, ranging from those explicitly delimited by
learners to those implied from their personal and collaborative
actions. On the one hand, a community space constitutes an
explicit context for potential interactions and learning revolving
around the community’s practices and involving its members, its
shared artefacts, as well as its eventual sub-activity spaces. On
the other hand, two or more actors commenting the same asset
could also form an implicit interaction context involving them,
the asset in question, its owner, and other contributors.
Identifying interaction and learning contexts is crucial in PLE
and is indeed more challenging than in traditional LMS. This is
mainly because PLE are not confined to preplanned
collaborative scenarios occurring within rigid and closed
collaboration spaces. Instead, it also accounts for smoother
forms of interactions that can evolve over time and induce both
intended and unintended learning situations.
      </p>
    </sec>
    <sec id="sec-5">
      <title>2.3 Offering elastic community and content management services</title>
      <p>
        Communities of practice (CoPs) are defined as a group of
individuals who choose to collaborate on a regular basis in order
to learn and improve their practices related to a shared passion
or topic of interest [
        <xref ref-type="bibr" rid="ref17">22</xref>
        ]. CoPs are considered to play a key role
in fostering knowledge sharing and learning [
        <xref ref-type="bibr" rid="ref18">23</xref>
        ]. This triggers
the motivation to sustain the initiation and evolution of CoPs in
professional and educational environments [
        <xref ref-type="bibr" rid="ref19">24</xref>
        ]. When it comes
to groupware systems, flexibility is a critical usability factor and
their design should take into account the possibility for groups to
evolve over time in terms of behavior, nature, and composition
[
        <xref ref-type="bibr" rid="ref20">25</xref>
        ]. The same should apply for the support of community
building and evolution in a PLE. Users enter their PLE as
individual actors and not as pre-labeled members of a rigid
organizational or institutional structure. Then, they can create
their self-organized communities [
        <xref ref-type="bibr" rid="ref21">26</xref>
        ] or deliberately join
existing ones, some of which may correspond to institutions and
organizations. With respect to rights managements, there ought
to be no pre-assumed hierarchy or default distribution of rights;
a person can be a learner in one community and a moderator in
another.
      </p>
      <p>
        With respect to content management, learners should be able to
create, share, modify, annotate, review and most importantly
repurpose learning artefacts ranging from books to Weblogs,
videos, podcasts and discussion archives [
        <xref ref-type="bibr" rid="ref22">27</xref>
        ]. Bringing together
heterogeneous information sources requires adopting
lightweight specifications such as RSS (Real Simple
Syndication or Rich Site Summary) [
        <xref ref-type="bibr" rid="ref23">28</xref>
        ] and creative commons2
licenses rather than strictly adhering to educational standards
(i.e. IMS3, SCORM4). Unlike traditional LMS where knowledge
objects are organized within learning units and their usage
anticipated, in a PLE, artefacts can exist outside the scope of
activity spaces; they can be shared directly among actors
without having to belong to an activity space or fall under the
2 http://creativecommons.org
3 http://www.imsglobal.org
4http://en.wikipedia.org/wiki/Sharable_Content_Object_Referen
ce_Model
umbrella of reaching an explicitly stated objective. Indeed, they
can at any time be posted in one or more activity spaces,
grouped together in a bottom-up way using tags, or explicitly
related to other artefacts. This approach increases the learning
flexibility and encourages the spontaneous appropriation of
knowledge artefacts.
      </p>
    </sec>
    <sec id="sec-6">
      <title>2.4 Providing personalized and contextual recommendation services</title>
      <p>
        PLE can be classified as “open corpus” environments [
        <xref ref-type="bibr" rid="ref24">29</xref>
        ]. In a
PLE, relationships between knowledge artefacts are not
necessarily known beforehand, as it is the case in traditional
hypermedia systems; instead, they can emerge, evolve, and
expand during run time. In addition, in online platforms where
everyone is a “consumer” and a “producer”, contributions differ
in quality, style, subject matter, target audience, composition,
and reliability. In such open environments, personalized and
contextualized recommendations can drive learners’ attention to
potentially interesting resources depending on their implicit or
explicit interests, therefore avoiding information overload, and
triggering formal and informal learning opportunities [
        <xref ref-type="bibr" rid="ref25 ref26">30,31</xref>
        ].
As mentioned earlier, PLE-embedded recommender systems can
exploit SALT actions performed by users on knowledge
artefacts and in different contexts in order to unobtrusively
leverage user interest [
        <xref ref-type="bibr" rid="ref27">32</xref>
        ].
      </p>
    </sec>
    <sec id="sec-7">
      <title>3. CONCLUSION</title>
      <p>This paper discussed four main factors deemed crucial for
developing PLE that are fit, ready for appropriation, and capable
of evolving over time: the adoption of social media paradigms,
the flexible representation of interaction and learning contexts
(including those explicitly defined by learners and those implied
from their actions), the incorporation of elastic community and
content management features encouraging the spontaneous
appropriation of knowledge objects, and finally the delivery of
personalized and contextualized recommendation services. We
are currently working on Graaasp5, an online PLE that builds on
the four PLE elements discussed in this paper.</p>
    </sec>
    <sec id="sec-8">
      <title>4. REFERENCES</title>
      <p>[1] Government of Ireland Stationery Office. (2000). Learning
for Life: White Paper on Adult Education. Dublin.
[2] Aspin, D., &amp; Chapman, J. (2007). Lifelong Learning:
Concepts and Conceptions. In D. Aspin (Ed.),
Philosophical Perspectives on Lifelong Learning.</p>
      <p>Dordrecht: Springer.
[3] Griffin, C. (1999). Lifelong Learning and Social
Democracy. International Journal of Lifelong Education ,
18 (5), 329-342.
[4] Colardyn, D., &amp; Bjornavold, I. (2004). Validation of
formal, non-formal and informal learning: policy and
practices in EU Member States. European Journal of
Education , 39 (1), 70-88.
[5] Cross, J. (2006). Informal Learning: Rediscovering the
Natural Pathways that Inspire Innovation and Performance.</p>
      <p>New Jersey: John Wiley and Sons.
5 http://graaasp.epfl.ch
[7]
emerge from collaborative verbosity. Proceedings of the
19th international conference on World Wide Web.
[20] Ackerman, M. (2001). The Intellectual Challenge of
CSCW: The Gap Between Social Requirements and
Technical Feasibility. In J. Carrol (Ed.), HCI in the New
Millennium. New York: Addison-Wesley.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [6]
          <string-name>
            <surname>Faure</surname>
            ,
            <given-names>E.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Herrera</surname>
            ,
            <given-names>F.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Kaddoura</surname>
            ,
            <given-names>A. R.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Lopes</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Petrovski</surname>
            ,
            <given-names>A. V.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Rahnema</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          , et al. (
          <year>1972</year>
          ). Learning to Be. Paris: Unesco.
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          <string-name>
            <surname>Wilson</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Liber</surname>
            ,
            <given-names>P. O.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Johnson</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Beauvoir</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Sharples</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          (
          <year>2007</year>
          ).
          <article-title>Personal Learning Environments: Challenging the dominant design of educational systems</article-title>
          .
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          <source>Journal of e-Learning and Knowledge Society</source>
          ,
          <volume>3</volume>
          (
          <issue>2</issue>
          ),
          <fpage>27</fpage>
          -
          <lpage>28</lpage>
          . Retrieved 2010
          <fpage>20</fpage>
          -January from http://je-lks.maieutiche.economia.unitn.it/index.php/Je-LK
          <string-name>
            <surname>S</surname>
          </string-name>
          _EN/article/viewFile/247/229
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          [8]
          <string-name>
            <surname>Taylor</surname>
            ,
            <given-names>F. P.</given-names>
          </string-name>
          (
          <year>2004</year>
          ).
          <article-title>Education technology helps unite school communities, improve academic achievements</article-title>
          . T.H.E. Journal ,
          <volume>31</volume>
          (
          <issue>10</issue>
          ),
          <fpage>46</fpage>
          -
          <lpage>48</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          [9]
          <string-name>
            <surname>Downes</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          (
          <year>2010</year>
          ).
          <article-title>New Technology Supporting Informal Learning</article-title>
          .
          <source>Journal of Emerging Technologies in Web Intelligence</source>
          ,
          <volume>2</volume>
          (
          <issue>1</issue>
          ),
          <fpage>7</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          [10]
          <string-name>
            <surname>Atwell</surname>
            ,
            <given-names>G.</given-names>
          </string-name>
          (
          <year>2006</year>
          1-
          <fpage>June</fpage>
          ).
          <source>Wales Wide Web. Retrieved</source>
          <year>2010</year>
          1
          <article-title>-May from Personal Learning Environments</article-title>
          : http://www.knownet.com/writing/weblogs/Graham_Attwell /weblog.archives/
          <year>2006</year>
          /6
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          [11]
          <string-name>
            <surname>Naeve</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Nilsson</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Palmér</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Paulsson</surname>
            ,
            <given-names>F.</given-names>
          </string-name>
          (
          <year>2005</year>
          ).
          <article-title>Contributions to a public e-learning platform: infrastructure; architecture; frameworks; tools</article-title>
          .
          <source>International Journal of Learning Technologies</source>
          ,
          <volume>1</volume>
          (
          <issue>3</issue>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          [12]
          <string-name>
            <surname>Van Harmelan</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          (
          <year>2006</year>
          ).
          <article-title>Personal Learning Environments</article-title>
          .
          <source>Proceedings of the 6th IEEE international conference on Advanced learning technologies</source>
          (pp.
          <fpage>815</fpage>
          -
          <lpage>816</lpage>
          ). Washington D.C.: IEEE Computer Society.
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          [13]
          <string-name>
            <surname>Grudin</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          (
          <year>1988</year>
          ).
          <article-title>Why CSCW applications fail: problems in the design and evaluation of organizational interfaces</article-title>
          .
          <source>Proceedings of the 1988 ACM conference on Computersupported cooperative work</source>
          (pp.
          <fpage>85</fpage>
          -
          <lpage>93</lpage>
          ). New York: ACM.
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          [14]
          <string-name>
            <surname>Garrett</surname>
            ,
            <given-names>J. J.</given-names>
          </string-name>
          (
          <year>2005</year>
          2-
          <fpage>18</fpage>
          ).
          <article-title>Ajax: A New Approach to Web Applications</article-title>
          .
          <source>Retrieved</source>
          <year>2010</year>
          20
          <article-title>-06 from AdaptivePath</article-title>
          .com: http://www.adaptivepath.com/ideas/essays/archives/000385 .php
        </mixed-citation>
      </ref>
      <ref id="ref11">
        <mixed-citation>
          [15]
          <string-name>
            <surname>Liccardi</surname>
            ,
            <given-names>I.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Ounnas</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Pau</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Massey</surname>
            ,
            <given-names>E.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Kinnunen</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Lewthwaite</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          , et al. (
          <year>2007</year>
          ).
          <article-title>The role of social networks in students' learning experiences</article-title>
          .
          <source>ACM SIGCSE Bulletin</source>
          ,
          <volume>39</volume>
          (
          <issue>4</issue>
          ),
          <fpage>224</fpage>
          -
          <lpage>237</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref12">
        <mixed-citation>
          [16]
          <string-name>
            <surname>Siemens</surname>
            ,
            <given-names>G.</given-names>
          </string-name>
          (
          <year>2004</year>
          12-
          <fpage>December</fpage>
          ).
          <article-title>Connectivism, A Learning Theory for the Digital Age</article-title>
          .
          <source>Retrieved</source>
          <year>2010</year>
          30- June from elearn space: http://www.elearnspace.org/Articles/connectivism.htm
        </mixed-citation>
      </ref>
      <ref id="ref13">
        <mixed-citation>
          [17]
          <string-name>
            <given-names>El</given-names>
            <surname>Helou</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            ,
            <surname>Li</surname>
          </string-name>
          ,
          <string-name>
            <given-names>N.</given-names>
            , &amp;
            <surname>Gillet</surname>
          </string-name>
          ,
          <string-name>
            <surname>D.</surname>
          </string-name>
          (
          <year>2010</year>
          ).
          <article-title>The 3A Interaction Model: Towards Bridging the Gap between Formal and Informal Learning</article-title>
          . International Conference on Advances in Computer-Human
          <string-name>
            <surname>Interaction</surname>
          </string-name>
          (pp.
          <fpage>179</fpage>
          -
          <lpage>184</lpage>
          ). Washington D.C.: IEEE Computer Society.
        </mixed-citation>
      </ref>
      <ref id="ref14">
        <mixed-citation>
          [18]
          <string-name>
            <surname>Farrell</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Lau</surname>
            ,
            <given-names>T.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Nusser</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Wilcox</surname>
            ,
            <given-names>E.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Muller</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          (
          <year>2007</year>
          ).
          <article-title>Socially augmenting employee profiles with people-tagging. The 20th annual ACM symposium on User interface software and technology</article-title>
          (pp.
          <fpage>91</fpage>
          -
          <lpage>100</lpage>
          ). New York: ACM.
        </mixed-citation>
      </ref>
      <ref id="ref15">
        <mixed-citation>
          [19]
          <string-name>
            <surname>Körner</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Benz</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Hotho</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Strohmaier</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Stumme</surname>
            ,
            <given-names>G.</given-names>
          </string-name>
          (
          <year>2010</year>
          ).
          <article-title>Stop thinking, start tagging: tag semantics</article-title>
        </mixed-citation>
      </ref>
      <ref id="ref16">
        <mixed-citation>
          [21]
          <string-name>
            <surname>Twidale</surname>
            ,
            <given-names>M. B.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Wang</surname>
            ,
            <given-names>X. C.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Hinn</surname>
            ,
            <given-names>D. M.</given-names>
          </string-name>
          (
          <year>2005</year>
          ).
          <article-title>CSC: computer supported collaborative work, learning, and play</article-title>
          .
          <source>Proceedings of the 2005 conference on Computer support for collaborative learning</source>
          (pp.
          <fpage>687</fpage>
          -
          <lpage>696</lpage>
          ).
          <source>International Society of the Learning Sciences.</source>
        </mixed-citation>
      </ref>
      <ref id="ref17">
        <mixed-citation>
          [22]
          <string-name>
            <surname>Wenger</surname>
            ,
            <given-names>E.</given-names>
          </string-name>
          (
          <year>1998</year>
          ).
          <article-title>Communities of practice: learning, meaning, identity</article-title>
          . Cambridge, UK: Cambridge University Press.
        </mixed-citation>
      </ref>
      <ref id="ref18">
        <mixed-citation>
          [23]
          <string-name>
            <surname>LaContora</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Mendonca</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          (
          <year>2003</year>
          ).
          <article-title>Communities of practice as learning and performance support systems</article-title>
          .
          <source>Information Technology: Research and Education</source>
          ,
          <year>2003</year>
          (pp.
          <fpage>395</fpage>
          -
          <lpage>398</lpage>
          ). Washington D.C.: IEEE Computer Society.
        </mixed-citation>
      </ref>
      <ref id="ref19">
        <mixed-citation>
          [24]
          <string-name>
            <surname>Stanoevska-Slabeva</surname>
            ,
            <given-names>K.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Schmid</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          (
          <year>2000</year>
          4-
          <fpage>January</fpage>
          ).
          <article-title>A generic architecture of community supporting platforms based on the concept of media</article-title>
          .
          <source>Proceedings of the 33rd Hawaii international conference on System sciencesVolume 1</source>
          (p.
          <fpage>1014</fpage>
          ). Washington D.C.:IEEE Computer Society.
        </mixed-citation>
      </ref>
      <ref id="ref20">
        <mixed-citation>
          [25]
          <string-name>
            <surname>Dourish</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          (
          <year>1992</year>
          ).
          <article-title>Applying Reflection to CSCW Design</article-title>
          .
          <source>Position paper presented at Workshop on "Reflection and Metalevel Architecture" European Conference on ObjectOriented Programming</source>
          . Utrecht, Netherlands.
        </mixed-citation>
      </ref>
      <ref id="ref21">
        <mixed-citation>
          [26]
          <string-name>
            <surname>Rocha</surname>
            ,
            <given-names>L. M.</given-names>
          </string-name>
          (
          <year>1998</year>
          ).
          <article-title>Selected Self-Organization And the Semiotics of Evolutionary Systems</article-title>
          . In S. Salthe, G. G. Van de Vijver, &amp; M. Delpos (Eds.),
          <source>Evolutionary Systems: The Biological and Epistemological Perspectives on Selection and Self- Organization</source>
          (pp.
          <fpage>341</fpage>
          -
          <lpage>358</lpage>
          ). Kluwer Academic Publishers.
        </mixed-citation>
      </ref>
      <ref id="ref22">
        <mixed-citation>
          [27]
          <string-name>
            <surname>Downes</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          (
          <year>2007</year>
          ).
          <article-title>Learning Networks in Practice</article-title>
          . (D. Ley, Ed.)
          <source>Emerging Technologies for Learning</source>
          ,
          <volume>2</volume>
          ,
          <fpage>19</fpage>
          -
          <lpage>28</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref23">
        <mixed-citation>
          [28]
          <string-name>
            <surname>Pilgrim</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          (
          <year>2002</year>
          18-
          <fpage>December</fpage>
          ).
          <source>What is RSS? Retrieved</source>
          <year>2010</year>
          30-June from XML: http://www.xml.com/pub/a/2002/12/18/dive-into-xml.html
        </mixed-citation>
      </ref>
      <ref id="ref24">
        <mixed-citation>
          [29]
          <string-name>
            <surname>Brusilovsky</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Henze</surname>
            ,
            <given-names>N.</given-names>
          </string-name>
          (
          <year>2007</year>
          ).
          <article-title>Open Corpus Adaptive Educational Hypermedia. The adaptive web: methods and strategies of web personalization</article-title>
          ,
          <fpage>671</fpage>
          -
          <lpage>696</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref25">
        <mixed-citation>
          [30]
          <string-name>
            <surname>Koper</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Tattersall</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          (
          <year>2004</year>
          ).
          <article-title>New directions for lifelong learning using network technologies</article-title>
          .
          <source>British Journal of Educational Technology</source>
          ,
          <volume>35</volume>
          (
          <issue>6</issue>
          ),
          <fpage>689</fpage>
          -
          <lpage>700</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref26">
        <mixed-citation>
          [31]
          <string-name>
            <surname>Tang</surname>
            ,
            <given-names>T.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>McCalla</surname>
            ,
            <given-names>G.</given-names>
          </string-name>
          (
          <year>2009</year>
          ).
          <article-title>A Multidimensional Paper Recommender: Experiments and Evaluations</article-title>
          . Internet Computing, IEEE ,
          <volume>13</volume>
          (
          <issue>4</issue>
          ),
          <fpage>34</fpage>
          -
          <lpage>41</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref27">
        <mixed-citation>
          [32]
          <string-name>
            <given-names>El</given-names>
            <surname>Helou</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            ,
            <surname>Gillet</surname>
          </string-name>
          ,
          <string-name>
            <given-names>D.</given-names>
            , &amp;
            <surname>Salzmann</surname>
          </string-name>
          ,
          <string-name>
            <surname>C.</surname>
          </string-name>
          (
          <year>2010</year>
          ).
          <article-title>The 3A Ranking System: Contextual, Personalized &amp; Simultaneous Recommendation of Actors, Activities &amp; Assets</article-title>
          .
          <source>Journal of Universal Computer Science, on Context-aware Recommender Systems</source>
          , In press
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>