Implementation of ELWMS.KOM

ELWMS.KOM is a platform for supporting self–directed RBL. It focuses on web resources as LRs, and therefore is implemented as an add–on to the web browser Firefox10, as commonly the web browser is the “window to the Web”. It allows learners to store whole or partial web resources and to build a knowledge network by employing semantic tagging. A knowledge network is a structure based on se- mantic networks, which [183] describes as “a graphical notation for representing knowledge in patterns of interconnected nodes and arcs”. Semantic tagging is an extended form of tagging that introduces an additional type to plain–text tags. This allows learners to mark a tag as a special semantic entity, e.g. disambiguating the tag “Paris” as a Location with the mythological Trojan Person “Paris”. Further, it allows assigning non–topical tags to resources that provide personal retrieval hints, e.g. stating on which

Event a certain paper or talk was given like “EC–TEL 2009” or who recommended a certain paper like

the Person “Dinsdale”. ELWMS.KOM provides default tag types, but a learner can easily define her own tag types [29]. The tagging process creates relations between tags and resources, and co–occurrences of identically typed tags allow inferring over non–explicit relations.

Knowledge networks exist in two granularities, for one there is a personal knowledge network that represents the tags and resources of one learner. Further, there is the community knowledge network that encompasses the knowledge networks of all learners combined. As learning is often a social process (cf. section 2.3), this community knowledge network enables the interaction, retrieval and collaboration across personal borders.

For providing a central storage of knowledge networks, a server–based approach has been chosen for the implementation of ELWMS.KOM. It uses the graph database and back–end K–Infinity11 for storing all users’ knowledge networks. K–Infinity provides the underlying graph database that is accessed via the KEM–API and a web application (the Knowledge Portal) that enables users to view and browse their knowledge networks. ELWMS.KOM consists of a WSDL web service that connects to the KEM–API and 10 _{http://www.mozilla.com/firefox, retrieved 2010-11-17}

11 _{http://www.i-views.de/web/index.php%3Foption=com_content&task=view&id=13&Itemid=45&lang=de_DE.html,} retrieved 2011-03-17

Architecture

Firefox

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Figure 2.5:Architecture of all components of ELWMS.KOM. The server side components are provided by K–

Infinity, the web service and the Firefox add–on are parts of ELWMS.KOM. The arrows denote inter–

component communication.

the Firefox add–on programmed in XML User Interface Language (XUL) and Java that provides the user interface to the learner and communicates with the web service. Figure 2.5 shows the general architecture of all components.

ELWMS.KOM is integrated in the Firefox sidebar, therefore it provides an unobtrusive user interface that can be accessed while browsing without switching windows or starting a new program. The follow- ing relevant functionalities are accessible via the sidebar (cf. figure 2.6):

1. Importing a selected web resource (snippet). On importing, a window is opened where semantic tags can be assigned (see figure 2.7).

2. Recommendations. If the web resource that is currently browsed is already in the community knowledge network, in this area different recommended web resources are displayed. The rec- ommendation process relies on structural properties of explicit relations between the current and recommended web resources.

3. The goal hierarchy. ELWMS.KOM allows learners to plan and structure their learning process by setting Goals. This is described in detail in chapter 6.

4. Activity stream. In this panel, small screenshots of the last persisted web resources are displayed. This enables learners to reflect on the resources they have already added and allows a quick access to resources that are relevant in the current learning episode.

Learners are enabled to set goals before starting a subsequent long–term learning process. These goals can be marked as “activated”, so that all persisted resources are automatically tagged with the active goal. This serves to quickly search for and collect relevant resources without having to manually assign them to the current goal. When a web resource is stored, the learner can add tags to the resource. Currently, there is a base ontology of tags supported by ELWMS.KOM that consists of the types plain text

Figure 2.6:The ELWMS.KOM sidebar is embedded on the left side of Firefox. It displays (from top to bottom) import functionality by selection and drag & drop, a recommendation panel, the goal hierarchy and the activity stream.

Tags, Topics, Persons / Organizations, Locations, Events, Type of the resource (e.g. whether it is a paper, a blog or a PDF file) and Goals. For a discussion of these types, see [30].

Figure 2.7:The web resource tagging view of ELWMS.KOM. The top panel contains the minimal metadata of a web resource: the title, a description or snippet and the URL. The lower panels contain the semantic tagging functionality and tag recommendations based on structural properties of the knowledge network.

For retrieval of the stored resources, learners can use the Knowledge Navigator to browse their personal as well as the community knowledge network using either the HTML view or a graphical display of the network structure. There are recommendations given based on the structure of the knowledge network and the ELWMS.KOM sidebar provides a listing of all web resources and tags per tag type. Export of the knowledge network is available in several formats; for example, scientific resources can be exported as BibTeX references and the goal hierarchy and all assigned snippets can be output as HTML.

ELWMS.KOM thus aims at supporting all process steps of RBL (cf. section 2.5.1) and constitutes the framework for all contributions of this thesis.