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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>ReMashed - Recommendation Approaches for Mash- Up Personal Learning Environments in Formal and Informal Learning Settings</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Hendrik Drachsler</string-name>
          <email>hendrik.drachsler@ou.nl</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Dries Pecceu</string-name>
          <email>pecceu@studie.ou.nl</email>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Tanja Arts</string-name>
          <email>tg.arts@studie.ou.nl</email>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Edwin Hutten</string-name>
          <email>ekh.hutten@studie.ou.nl</email>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Lloyd Rutledge</string-name>
          <email>lloyd.rutledge@ou.nl</email>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Peter van Rosmalen</string-name>
          <email>peter.vanrosmalen@ou.nl</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Hans Hummel</string-name>
          <email>hans.hummel@ou.nl</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Rob Koper</string-name>
          <email>rob.koper@ou.nl</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Centre for Learning Sciences and Technologies &amp;</institution>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Computer Science Department</institution>
          ,
          <addr-line>PO-Box 2960, 6401 DL Heerlen</addr-line>
          ,
          <country country="NL">The Netherlands</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Open University of the Netherlands</institution>
        </aff>
      </contrib-group>
      <fpage>23</fpage>
      <lpage>30</lpage>
      <abstract>
        <p>This article presents the ReMashed system that recommends learning content from emerging information of a Mash-Up Personal Learning Environment. ReMashed offers advice to find most suitable learning content for individual competence development of lifelong learners. The ReMashed system was initially designed to offer navigational support to lifelong learners in informal learning settings. In this article we want to discuss its ability to be used also in formal learning settings. For this purpose, we discuss the use of two different recommendation approaches for formal and informal learning within ReMashed.</p>
      </abstract>
      <kwd-group>
        <kwd>recommender system</kwd>
        <kwd>mash-up</kwd>
        <kwd>personalization</kwd>
        <kwd>personal learning environments</kwd>
        <kwd>MUPPLE</kwd>
        <kwd>informal learning</kwd>
        <kwd>emergence</kwd>
        <kwd>formal learning</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1 Introduction</title>
      <p>The networked Knowledge Society is more than ever empowered by the Web2.0
development efforts. The so called Web2.0 lifted the barrier of adding information to
the Internet and enables people to contribute information to the Internet. This also
applies to lifelong learners who use the Internet to find suitable information for their
learning needs. They also take advantage of Web2.0 tools to create, share, and use
learning activities.</p>
      <p>
        Nowadays, Internet users and lifelong learners can take advantage of services like
iGoogle or Netvibes to create a personal view on information they are interested in.
iGoogle and Netvibes are Mash-up Personal Environments that allows their users to
add and combine different information sources of the Internet at one place. Further,
by integrating Web2.0 services like Blogs, Delicious or Slideshare the user can follow
other users and integrate social networks into such a Mash-up Personal Environment.
Consequently the concept of Mash-Up Personal Learning Environments is also
applied to support learning. They are called Personal Learning Environments (PLEs)
[
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] or Mash-Up Personal Learning Environments (MUPPLEs) [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ].
      </p>
      <p>
        MUPPLEs initially support informal learning as they require no institutional
background, curriculum structure, and are free of use. Their focus is on the learner
independently from institutional needs like student management or assessments.
Although, they are most appropriate for informal learning, educational scenarios are
thinkable where MUPPLEs become integrated into formal learning like in universities
as well. In an even more complex manner the existing of MUPPLEs force universities
to open up their environments and services to MUPPLEs [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ].
      </p>
      <p>The possibilities of the Web2.0 tools and Mash-Up Personal Environments
increase the amount of information available on the Internet and enables people to
access almost anything they need. On the other hand, the Internet opens the door for a
plethora of information that makes it difficult to get an overview and to select the
most suitable information. This selection problem also applies to lifelong learners
who get lost on the Internet. The learners can be overwhelmed by the information
they receive or they might have problems selecting the most suitable learning content
for their personal competence development.</p>
      <p>Promising technologies to support people, in order to navigate to the most suitable
information, are recommender systems. They are successfully applied at e-commerce
web sites like Amazon.com, where people receive recommendations based on the
products they are interested in. The recommender system matches customers with a
similar taste of products and creates a kind ‘neighborhood’ of like-minded customers.
It looks for related products purchased by the neighbors and recommends these to the
current customer. This navigational support by recommender systems may help us to
reduce time and costs involved in selecting suitable information on the Internet. It will
help learners in selecting learning content according to their individual needs,
preferences and learning goals.</p>
      <p>This article presents the ReMashed system, a MUPPLE that exists out of mashed
information from Web2.0 services and a recommender system that offers advice to
find most suitable learning content for individual competence development of lifelong
learners. The ReMashed system was initially designed to offer navigational support to
lifelong learners in informal learning settings. In this article we want to discuss its
ability to be used also in formal learning settings.</p>
      <p>In the following section we present first related work on MUPPLEs (section two).
Afterwards we present the ReMashed system in version 1.0 (section three). After that
we present two recommendation approaches for using ReMashed either in formal or
informal learning settings (section four) and finally discuss future research (section
five).</p>
    </sec>
    <sec id="sec-2">
      <title>2 Related work</title>
      <p>Nowadays, ‘mashing’ information becomes a widely used activity on the Internet. In
order to get an overview of conducted research on MUPPLEs we created a Mindmap
that shows related research topics around MUPPLEs 1.
1 The Mindmap can be found at http://www.mindmeister.com/15237440/r-d-on-mupples. Feel
free to join us and further extend it.</p>
      <p>We identified three main research fields on MUPPLEs: 1. Pedagogical scenarios,
2. Use case studies, and 3. Technology Development. Surprisingly, research field 3 –
Technology Development contains most of all published articles. Because of the size
of this article we can hardly discuss all related research efforts. Nevertheless, we want
to give some examples for each research field and recommend to have a look on the
online version of the Mindmap.</p>
      <p>
        According to research field 1, there are multiple pedagogical scenarios thinkable a
good example for using a MUPPLE in formal learning can be found in [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. They
present an approach how universities can take advantage of MUPPLEs. An example
how MUPPLEs support informal learning can be found in [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. For research field 2 –
Use case studies, we have to point to [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ] where four experiments with MUPPLEs are
reported. According to research field 3 – Technology Development, various efforts
are published. For instance [
        <xref ref-type="bibr" rid="ref6 ref7">6, 7</xref>
        ] have different approaches to make the development
of MUPPLEs more end-user friendly, further [
        <xref ref-type="bibr" rid="ref8 ref9">8, 9</xref>
        ] try to improve the information
interoperability between widgets in MUPPLEs.
      </p>
      <p>The ReMashed system belongs to research field 3 – Technology Development of
MUPPLEs and extends the already existing developing efforts with recommender
system research. It offers navigation support for lifelong learners to meet most
suitable learning content in Mash-Ups. The combination of different Web2.0 services
to recommend information based on mashed tag and rating data was not done so far
and especially not for learners in MUPPLEs. Thus, ReMashed offers a new approach
by mashing data of users from various Web2.0 services to provide tailored
recommendation to them.</p>
    </sec>
    <sec id="sec-3">
      <title>3 The ReMashed System</title>
      <p>
        In order to test different recommendation approaches for MUPPLEs we designed the
ReMashed environment that enables lifelong learners to add their Web2.0 sources to
the ReMashed community. The system allows the learners to personalize emerging
information of a community to their preferences. They can rate information of the
Web2.0 sources in order to define which contributions of other members they like and
do not like. ReMashed takes the preferences into account to offer tailored
recommendation to the learner. It uses collaborative filtering [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ] to generate
recommendations by matching together learners with similar opinions about learning
resources. Each member of the system has a 'neighborhood' of other like-minded
learners. Ratings and tags from these neighbors are used to create personalized
recommendations for the current learner. The recommender system combines tag and
rating based collaborative filtering algorithms in a recommendation strategy. Such a
recommendation strategy reacts on certain situations by using the most suitable
recommendation technique. We tested a prototypical version of the system (Version
0.9) in an usability evaluation in a group of 49 users from 8 different countries [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ].
The evaluation phase ran for one month and was concluded with an online recall
questionnaire. In that timeframe 4961 contents were collected, 420 resources were
rated and 813 recommendations were offered. The overall satisfaction with the system
was positive. The participants suggested particular improvements we took into
account for ReMashed release 1.0 (see Fig. 1). The goals of ReMashed and a detailed
system architecture can be found in [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ]. Currently, Version1.0 supports the Web2.0
services Twitter, flickr, RSS feeds from Blogs, slideshare, delicious, and YouTube.
Fig. 1. The user interface of the ReMashed 1.0. On the left side, the mashed information from
delicious, blogs, flickr and slideshare are shown. On the right side, the recommendations for the
current learner are presented.
      </p>
      <p>In order to support the learners with suitable recommendations for learning we
extended the user profile with a learning goal specification and related knowledge
level definition. The learners can specify three main learning goals with their current
knowledge level. They can specify their knowledge levels in a self-assessed way (see
Fig. 2).</p>
      <p>
        We supported the learning goal interface by a simple auto-suggest / auto-completion
algorithm [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ] which can be fed by different technologies like ontologies, metadata,
existing tags, or already entered learning goals of other learners.
      </p>
      <p>Initially ReMashed was designed to support lifelong learners in informal learning
processes but as Web2.0 is also an important topic for companies and universities we
want to explore the application of ReMashed also for formal learning settings.
Therefore, ReMashed can be further developed for information dissemination and
managing tasks within organizations. Because organizations often have classified
information more restricted tools for information sharing are needed. Free accessible
Web2.0 services that are open to the Internet can hardly be applied for this purpose.
Thus, a kind of closed IntraWeb2.0 solutions (own blogging or twitter system) could
be used within the organizations to strengthen the knowledge dissemination. The
produced content could emerge in similar interfaces like the suggested ReMashed
system, without fearing to lose classified information to third parties. In addition,
companies or universities might have more restricted learning goals than individual
lifelong learners. Therefore, we have to adjust the recommendation approach to
certain conditions of formal and informal learning settings.</p>
      <p>In the following section we discuss the changes in recommendation approaches to
support formal and informal learning settings with ReMashed.</p>
    </sec>
    <sec id="sec-4">
      <title>4 Recommendation approaches for formal and informal learning settings</title>
      <p>Different recommendation needs can be identified when considering the use of
Technology-Enhanced Learning (TEL) to support different educational settings like
formal and informal learning.</p>
      <p>
        Formal education, being usually organized according to some curriculum,
traditionally occurs in teacher-directed environments with person-to-person
interactions. Informal learning is described in literature as a learning phase of so
called lifelong learners who are not participating in any formal learning context (like
universities or schools). Lifelong learners are acting much more self-directed and they
are responsible for their own learning pace and path [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ]. In addition, the learning
content for their learning might come from many different sources: expert
communities, work context, training or even friends might offer an opportunity for an
informal competence development. The learning process is also not designed by an
institution or responsible teachers like in formal learning, but it depends to a large
extent on individual preferences learners have or choices that learners take.
      </p>
      <p>Depending on the learning settings, the aims of TEL systems, their environmental
conditions, and the tasks that they support also change. Thus, considering the way
TEL context variables vary according to the adopted setting, the information needs of
the targeted users change. This can greatly affect the design of recommender systems
for different TEL settings. In the following sub section we suggest recommendation
approaches for formal and informal learning settings. We especially focus thereby on
the learning goal interface and its related knowledge levels in ReMashed. Both
approaches can feed the learning goal interface (see Fig. 2) to embed pedagogical
reasoning into the recommendation.</p>
      <sec id="sec-4-1">
        <title>4. 1 Recommendation approach for formal learning settings</title>
        <p>
          Many recommender systems for formal learning like [
          <xref ref-type="bibr" rid="ref15">15</xref>
          ] using fine granulated
knowledge domains and can therefore offer personalized recommendations to the
learners. They can use metadata and ontologies to define the relationships, conditions,
and dependencies of learning resources and learner models. They can take advantage
of well structured formal relationships like predefined learning plans (curriculum)
with locations, student/teacher profiles, and accreditation procedures to recommend
courses or personalize learning.
        </p>
        <p>
          A promising solution to apply the learning goal functionality of ReMashed for
formal learning settings is the work on adaptive sequencing [
          <xref ref-type="bibr" rid="ref16">16</xref>
          ]. It takes into account
individual characteristics and preferences for sequencing learning content. Adaptive
sequencing needs three abstraction layers to add semantics between content and
possible learning goals. On the top layer, the learning goal layer, a hierarchy of
learning goals needs to be modeled. In the second layer, the conceptual layer,
ontology of domain concepts needs to be created. The lowest layer, the content layer,
contains the actual content of the learners. With the adaptive sequencing approach
organizations can pre-structure and control the available learning goals within the
system. Further, they can easily adjust and cluster the learning goals and their related
knowledge level to their needs.
        </p>
        <p>This approach requires a maintenance effort as there are many design activities
needed before the runtime and also during the maintenance of the system. In addition,
the knowledge domains in the learning environment need to be described in detail.
These aspects make the adaptive sequencing approach not applicable for informal
learning settings.</p>
      </sec>
      <sec id="sec-4-2">
        <title>4. 2 Recommendation approach for informal learning settings</title>
        <p>
          In order to apply ReMashed for informal learning settings, we need different
recommendation approaches. The absence of maintenance and structure in informal
learning settings is also called the ‘open corpus problem’. The open corpus problem
applies when an unlimited set of documents is given that cannot be manually
structured and indexed with domain concepts and metadata [
          <xref ref-type="bibr" rid="ref17">17</xref>
          ]. For instance,
learning goals in informal learning settings are a rather diffuse parameter because
they rely on information given by the learners without any standardization.
        </p>
        <p>To handle the dynamic and diffuse characteristic of learning goals and related
knowledge levels probabilistic techniques like text driven latent semantic analysis or
mining techniques like hierarchical clustering are promising. They are appropriate for
informal learning settings because they require nearly no maintenance and improve
through the emergent behaviour of the community. ReMashed is not a purely text
based system, as it uses videos and pictures as well. Therefore a purely text-driven
approach is rather inappropriate. Most suitable therefore is the hierarchical clustering
method. It builds up a hierarchy of items by continuously merging the two most
similar items / groups into a new group. In the ReMashed case, an item is a single
blog posting or a picture with related tags. We can create a measure for most
frequently used keywords for each blog or picture by simply using words counts. The
similarity between items / groups can then be measured by similarity measures like
Euclidean distance or the Pearson correlation. In each iteration the method calculates
the distance between every pair of items / groups and the closet ones are merged
together to form a new group. This process is repeated until there is one group with
various sub groups. In that way hierarchical clustering creates a kind of automated
ontology on top of the available contents.</p>
        <p>Similar like the adaptive sequencing approach this automated ontology can be fed
into the learning goal interface in ReMashed and present the available learning goals
in the system.</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>5 Conclusions and Future Research</title>
      <p>This article presented the ReMashed system, an MUPPLE with a recommender
system for learners. The article presented related work in MUPPLE in section two.
Further it presented the ReMashed system in section three and discusses its
application for formal and informal learning settings by using different
recommendation approaches (section four).</p>
      <p>Based on formal or informal learning setting of learners recommendations have to be
done rather differently. In case ReMashed is applied in formal learning settings the
recommender system can take advantage of well structured formal relationships like
predefined learning plans (curriculum) with locations, student/teacher profiles, and
accreditation procedures to recommend learning resources to learners. Therefore,
more top-down technologies like ontologies and adaptive sequencing are suitable to
offer personalized recommendations.</p>
      <p>In order to apply ReMashed for informal learning settings, we need to take into
account a lack of structure and maintenance. Thus, to handle the dynamic and diffuse
characteristic of informal learning more bottom-up technologies like latent semantic
analysis or mining techniques like hierarchical clustering are needed. They are more
appropriate for informal learning settings because they require nearly no maintenance
and improve through the emerging behaviour of the community.</p>
      <p>In the future we want to explore most suitable recommendations approaches for the
use of MUPPLEs in formal and informal learning. Furthermore, we want to improve
interoperability of ReMashed to other MUPPLEs. Therefore, ReMashed has to
provide a widget interface to enable lifelong learners to integrate the
recommendations from ReMashed into their MUPPLEs. Such a widget should
provide recommendations and the possibility to rate content from the community to
further personalize the needs of the learners.</p>
    </sec>
    <sec id="sec-6">
      <title>Acknowledgement</title>
      <p>Authors’ efforts were (partly) funded by the European Commission in
TENCompetence (IST-2004-02787) (http://www.tencompetence.org).</p>
    </sec>
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