TOOLS TO FOSTER SEMANTIC-BASED COLLABORATION

A Knowledge Management Approach Based

on a Semantic Wiki and Personal Ontologies

Flavio De Paoli and Marco Loregian

Dipartimento di Informatica, Sistemistica e Comunicazione, University of Milano-Bicocca

via Bicocca degli Arcimboldi 8, 20126 Milano, Italy

Keywords:

Collaboration, Knowledge Management, Semantic Wiki, Ontology Editing.

Abstract:

Increased mobility and team distribution may hinder collaboration in organization by hampering spontaneous

communication in workplaces. Tools are required to be integrated and not intrusive with respect to users’

activities, in order to provide effective support to workers for the development of joint projects. In this paper

we present the enhancement of a knowledge-based collaborative system by means of a Semantic Wiki, which

is a wiki exploiting ontologies to create machine-processable annotation of documents. Moreover, we present

a simple tool to edit personal ontologies, that can be shared with other team or organization members.

1 INTRODUCTION

Being composed of several, often parallel activities

and tasks, business processes rely on active col-

laboration among participants. Several approaches

have been proposed for business process management

(BPM), mainly focusing on issues related to coordina-

tion among entities (van der Aalst et al., 2003). How-

ever, besides the planning of processes, spontaneous

communication among peers has an important role: it

usually takes place when people meet each other in

physical settings, casually or on purpose. With in-

creased mobility of users and distribution of teams,

such a possibility is at risk, and technological means

seem to be required to overcome the possible inability

of encountering colleagues and to foster spontaneous

participation in the evolution of projects.

The aim of this work is to propose the integration

of techniques that have already been proved success-

ful in world-scale situations into the smaller setting of

modern enterprises. In particular, we aim at present-

ing how to integrate Semantic Web and wiki technol-

ogy into a Knowledge Management (KM) system.

A KM system is a collaborative environment sup-

porting the workers of an organization in exchang-

ing knowledge by providing an environment to let

them share documents and supplying techniques to

associate a meaning with them — usually adopting

ontologies and proﬁling mechanisms. The reference

platform of this paper was designed as the result of

studies conducted on real settings to analyze the role

of (informal) communication and the way it is used in

articulating work tasks (Agostini et al., 2005).

In this paper, we present a set of features pro-

moting the involvement of people in creating and ex-

changing knowledge by providing them with an easy

way of publishing group knowledge. The chosen ap-

proach is to combine the deﬁnition and sharing of per-

sonal ontologies with the creation of proﬁles and an-

notations of documents using a wiki interface (Leuf

and Cunningham, 2001). A personal ontology is com-

posed of a set of terms and relations that are dy-

namically selected from available ontologies, possi-

bly augmented with user-deﬁned semantic extensions.

A tool to facilitate the deﬁnition and the evolution of

personal ontologies, their use in common activities,

such as Web browsing, and KM speciﬁc, such as doc-

ument proﬁling, is described.

2 FEATURES TO ENHANCE

COLLABORATIVE KM

This section starts with the outline of the general char-

acteristics of the reference KM platform used in our

302

De Paoli F. and Loregian M. (2007).

TOOLS TO FOSTER SEMANTIC-BASED COLLABORATION - A Knowledge Management Approach Based on a Semantic Wiki and Personal

Ontologies.

In Proceedings of the Third International Conference on Web Information Systems and Technologies - Web Interfaces and Applications, pages 302-307

DOI: 10.5220/0001286603020307

 SciTePress

experiments; next, the Semantic Wiki designed and

developed to support collaboration is presented with

its features and architecture; ﬁnally, a tool to edit the

personal ontologies to be used in the KM system is

described.

2.1 The Reference KM System

MILK

is a Knowledge Management system that al-

lows a community of persons to store, organize and

retrieve documents in a multimodal and multichannel

way. The system relies on a server-based architecture

encompassing a KM engine (the Metadata Manage-

ment System, MMS) that can be connected to hetero-

geneous archiving systems.

At KM level, MILK deﬁnes a proﬁling mecha-

nism that uniﬁes knowledge descriptions associated

with documents, people, projects and communities

(collectively named elements). Any kind of element

can be included in the same indexing and retrieval

process. So, for example, given the proﬁle of a

project, it is possible to collect information about any

other project that has similarities with the current one,

know who is interested in the same subject, and iden-

tify documents regarding the same topics. The pro-

ﬁling process is driven by ontologies that describe

speciﬁc domains: ontologies can be used to edit ele-

ments’ metadata, and are then exploited by the MMS

to compute correlations between elements — i.e., to

identify related topics (Boselli et al., 2003) .

At interaction level, the aim of the system is to

provide users with various contextualized interfaces

and interaction mechanisms that ﬁt different devices

and working situations, supply users with different

views over the same contents to promote awareness

and learning according to the activity a user is under-

taking (Agostini et al., 2005; Agostini et al., 2003).

In other words, user interfaces are requested to pro-

vide multimodal interactions according to different

user terminals.

The need of supplying multimodal and multichan-

nel presentation of documents — that is, to be able

to present the same document in different formats ac-

cording to the most suitable device currently available

to the user — led to a key choice in the information

architecture of the system. Documents are composed

of a collection of ﬁles, each one proposing a repre-

sentation of the actual content of a document. For

example, for each document might, or rather should,

exist a representation that is well-suited for a regu-

lar PC (e.g., the full pdf version of a paper), one for

Multimedia Interaction for Learning and Knowing,

IST-2001-33165, http://www.cootech.disco.

unimib.it/milk/

Figure 1: The MILK desktop client GUI, showing the

“View With Context” presentation.

large displays (e.g., a slide-show presenting the con-

tent), and one for handheld devices (e.g., the textual

abstract of the paper). It is important to remark that

all these ﬁles should be considered as being the same

document or, at most, different views of the same doc-

ument. Thanks to proﬁling, the system is able to man-

age the different representations as “attachments” to

the same element.

The most general representation of a document is

its proﬁle, a set of metadata that is stored by the sys-

tem, that can be edited by users using a (standalone or

web-based) client, and that can be enriched by means

of Semantic Web technology (RDF) and successful

interaction techniques (wiki-style collaboration). On-

tologies ﬁtting users’ needs are essential to achieve

good results in supporting work practices.

In order to easily exploit ontologies in element

proﬁles, the GUI provides a standard way to visual-

ize and use ontology terms, as keywords, in document

proﬁles: a panel displays such terms in a classic tree

fashion from which a term can be added to an element

proﬁle by simply dragging and dropping it. Other-

wise, terms can be manually entered by typing them

in the appropriate form ﬁelds. Typed terms can be

part of the ontology or new keywords. In the latter

case, they are collected and proposed to the autho-

rized administrators of the system as candidate terms

for a reference ontology that is shared organization-

wide.

2.2 Collaborative Knowledge Creation

The system helps people to manage information and

easily access the right sources for creating new con-

tents (Agostini et al., 2003). In most KM systems,

users are enabled to search repositories to get infor-

mation; instead, MILK supports users to discover in-

TOOLS TO FOSTER SEMANTIC-BASED COLLABORATION - A Knowledge Management Approach Based on a

Semantic Wiki and Personal Ontologies

303

Figure 2: A detail of the Wiki perspective embedded in the

KM client.

formation while they are using the system. The dis-

covery is supported by automatically computing and

presenting information that are related to what the

user is doing and displaying on the screen. Figure 1

illustrates the concept in a prototype (desktop PC) in-

terface that displays a document surrounded by ele-

ments that are related to the content of that document.

This interface style is named “view with context” to

say that any displayed element is surrounded by its

context.

The current GUI is a standalone application, built

on Eclipse Rich Client Platform

. The advantage of

this choice is to deliver a (cross-platform) tool that

is easily extensible, via plug-ins, to allow for rapid

prooﬁng of new ideas.

The interface is structured in perspectives that col-

lect related views. For example, the “View with Con-

text perspective” is composed of a main view sur-

rounded by smaller panels displaying ontologies, re-

lated elements, project structure, and available peo-

ple (Fig 1). The main view (i.e., the so-called edit

metadata view) is essentially form-based, meaning

that metadata is entered in proﬁles by ﬁlling in the

ﬁelds of a form. In Computer Supported Cooperative

Work (CSCW) literature, this task has been widely

recognized to be tedious. In particular, this kind of

interaction is not perceived as a collaborative activity.

Forms suggest a rigid conception of proﬁles, whereas

the Metadata Management System was designed for

more ﬂexibility (e.g., to deal with heterogeneous ele-

ments).

On the other hand, the popularity of tools such as

Wikipedia (Giles, 2005) shows that wiki-style interac-

tion could be the key factor to allow users to generate

new contents by completing existing element proﬁles

with information that can be easily edited (with ele-

mentary wiki syntax) and exploited, for example, to

build richer views on the knowledge base.

For these reasons, we are testing a “Semantic Wiki

perspective” in the RCP client (Figure 2). Users can

annotate elements’ proﬁles as free-text, and we claim

http://www.eclipse.org/rcp/

Firefox Extension

Personal Ontology

MILK client

MILK wiki

parser

(Jena)

wiki interface

article

view

editor

view

metadata

view

source

view

Ontology

Management

Metadata

Management

Users Management

Organization

Reference Ontology

Document

Repository

Figure 3: The architecture of the system: only elements

relevant to the wiki perspective are shown.

it to be a semantic wiki because of the enhancement

it carries in knowledge processing, being tightly in-

tegrated with system ontologies. The deﬁnition of

a wiki representation enhances the content manage-

ment capabilities of the system, for example to sup-

port more precise computation of the view with con-

text, taking annotations into account.

At a basic level, annotations can be associated

with a document by simply selecting words or sen-

tences in the text area and then dragging one or more

terms from the ontology view on them. By this ac-

tion, a RDFa

annotation is created in the document,

and the user perceives it through the change of the

annotated portion of the text that turns underlined.

The semantic wiki was designed according to a

simple, yet consolidated architecture (Oren et al.,

2006) (Figure 3). In the user interface, four main

views are currently available:

• the article view is a read-only display of the wiki

representation of the document. With this view

users can get general view over the annotations

on a document: annotations are associated with

underlined text. Using mouse roll-over tooltips it

is possible to view annotation details. Using an

HTML template, with XSLT and CSS technolo-

gies, the wiki description can be rendered on a

range of devices or exported in various formats,

with various appearances;

• the editor view presents a compact editable view

of the document: the text and the annotation can

be modiﬁed by picking terms from the available

ontologies. Also in this view, annotations are only

associated with underlined text;

• the edit metadata view collects the list of generic

metadata and the annotations in a form: metadata

http://www.w3.org/TR/

xhtml-rdfa-primer/

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304

Figure 4: The Mozilla Firefox extension, and the main in-

teraction steps to deﬁne a personal ontology by adding a

new term.

can thus be quickly edited and the changes are au-

tomatically inserted in the wiki ﬁle;

• the source view allows the user to directly edit the

source code of the wiki ﬁle (i.e., RDFa annota-

tions): tags are shown and can be directly edited

in the body of the document.

When a document is saved, the MMS is in charge

of parsing the wiki ﬁle (the wiki perspective relies on

Jena APIs to generate documents) to extract informa-

tion and update the document proﬁle accordingly. The

RDFa representaion is stored in the repository along

with other representations and documents.

2.3 How to Create Personal Ontologies

In its original release, the MILK system was limited

to rely only on a centralized ontology. Such ontol-

ogy was designed in different versions to accommo-

date the needs of the test settings in which the system

was deployed. Generic APIs and graphical user in-

terfaces were implemented to directly manipulate on-

tologies. Ontology maintenance required administra-

tors that were familiar with basic principles of knowl-

edge engineering and with MILK technology.

A goal of our work is to design features that allow

individuals to easily deﬁne personal ontologies, pos-

sibly grounded on those published on the Web, that

can be shared with colleagues, instead of only allow-

ing users to type new keywords. Our approach is to

integrate an ontology creation process with the most

common desktop activity: Web browsing.

In the everyday activity, we use the Web to ex-

tend our knowledge by learning from documents and

from terms exploited in the searching. We are con-

ducting experiments that aim to extend the system

beyond the basic activities on shared ontologies and

repositories to include the terms used during brows-

ing as personal ontology terms. We are testing an ex-

tension of Mozilla Firefox that monitors the queries

sent to search engines, e.g., Google (Figure 4). The

extension is called OntoMarks and can be down-

loaded from the following URL: http://www.

cootech.disco.unimib.it/ontomarks/.

The user interface of the browser extension con-

sists of a sidebar with an upper “permanent” panel,

and a lower “temporary” panel. Whenever a Google

page is loaded, the keywords used in the search are ex-

tracted by parsing the page URL and added to the bot-

tom panel of the sidebar (step 1 in Figure 4). By right-

clicking on any of the keywords currently displayed,

the user can search the term again with Google (like

with a bookmark) or make the keyword part of a

permanent set (step 2 in Figure 4). Searches with

multiple keywords are split, but expressions between

quotes are kept as a single keyword. The list of key-

words in the panel is temporary, and it is reset every

time Firefox is started.

When a keyword is selected to be included in the

personal ontology, a query can be sent to Swoogle

via its Web Service APIs, to ﬁnd out if the term is de-

ﬁned by available ontologies. A new browser tab is

opened to show the matching results and let the user

select the most appropriate term by reading available

descriptions. The insertion in the personal ontology

can be postponed, and the found terms are temporar-

ily saved and accessible via a contextual menu that

can be open by right-clicking on the already searched

term. A colored dot shows the status of a term: red

for terms that have not been searched or that have not

been found on Swoogle, green otherwise.

If a term from an existing ontology is chosen, then

a complete copy of its deﬁnition (description, proper-

ties, relations) is added to the personal ontology, so to

be available for future use, for example when the on-

tology is shared with other team/organization mem-

bers (Section 2.4)

Besides using terms as bookmarks for Google

searches, the general utility of creating a personal on-

tology is to use it in KM systems such as MILK (i.e.,

by loading and using it in the GUI) to better orga-

nize personal knowledge or retrieve information from

a shared repository: needless to say, it is the vision of

the Semantic Web (Berners-Lee et al., 2001).

For this reason, this plug-in is compliant with Se-

mantic Web technologies: the upper panel relies on a

RDF ﬁle that permanently stores a user’s personal on-

tology, that can be loaded and managed by the client

GUI as well as by any other RDF-based application.

http://swoogle.umbc.edu/

TOOLS TO FOSTER SEMANTIC-BASED COLLABORATION - A Knowledge Management Approach Based on a

Semantic Wiki and Personal Ontologies

305

2.4 How to Share Personal Ontologies

MILK’s KM engine can supply contextualized ac-

cess to document repositories, through different in-

terfaces, and can load personal ontologies from lo-

cal hard drives and from the Internet (via URIs). By

doing so, users can request the MMS for customized

views on the knowledge base. However, to support

cooperation, personal ontologies might be needed as

shared resource (in parts or as a whole) since they are

referenced by proﬁles and wiki annotations. More-

over, they can be a vehicle to spread new knowledge.

The system supports access to a shared reference

ontology, that is maintained by administrators and to

which all organization users can contribute by adding

new terms (De Paoli and Loregian, 2006b). More

precisely, users can propose new candidate terms, by

simply using them in document proﬁles, and admin-

istrators have the task of accepting them. Adminis-

trators have actually the more complex role of keep-

ing the reference ontology consistent with the orga-

nization activities, and to supply additional informa-

tion (e.g., relations among terms) in order to allow

the MMS to effectively compute correlations among

terms and, therefore, to enable mechanisms such as

the already mentioned view with context.

Annotations can carry different amounts of infor-

mation, according to the technique adopted by the

users: (i) if a new term is simply typed in a proper

form ﬁeld, no additional semantic information (i.e.,

deﬁnitions, properties, and relations with other terms)

is provided. In this case, the keyword is a simple

candidate term, and administrators have to possibly

provide its semantics; (ii) if a term is dragged and

dropped from a personal ontology, an ontology frag-

ment, rather than just a term, is proposed as a candi-

date. By fragment we mean a term with all its known

relations, possibly along with other involved terms. In

this case administrators can take advantage of existing

references, or they can use the original ontology (from

which the term was chosen and taken by the user) as

a complete reference.

Annotations can help administrators’ tasks by pro-

viding the context in which a term was used, and also

end-users can extend their knowledge of a speciﬁc

topic by looking for annotations referring to a speciﬁc

term.

3 RELATED WORKS

The work presented in this paper took inspiration

from other efforts made in developing semantic wikis.

Among others, SEMPERWIKI (Oren et al., 2006), and

IkeWiki (Schaffert, 2006). While other wikis have

been designed as standalone tools, with the purpose

of creating homogeneous, yet processable knowledge

bases, the project described here aims at going a step

further. With respect to KM, it seems rather unreal-

istic to consider wikis apart from other existing and

already adopted collaborative tools, or as a new tech-

nology to be applied only when starting to build new

collaborative knowledge bases. Thanks to the sim-

plicity with which annotations can be added to ex-

isting documents, wikis should instead be integrated

with technologies in use. In this paper we have dis-

cussed the integration with the MILK system, which

relies on a ﬁle system managed by an FTP server. An

advantage of this technique is that the integration can

be fully transparent to end users, which may decide

to ignore the feature. Other integration experiments

could be carried on with respect to other existing doc-

ument management platforms, such as BSCW (for-

merly adopted in MILK) (Agostini et al., 2005).

Moreover, thanks to the reuse of semantic termi-

nologies — enabled by the ability of the MILK client

to load ontologies from various locations and by the

Firefox extension to edit personal ontologies — users

can be supported all across their main working and

learning activities without forcing them to drop the

tools to which they are familiar with.

The browser-extension approach is already widely

in use to enrich the browsing experience with addi-

tional information. For example, an extension called

Semantic Turkey has also been developed to edit on-

tologies within the browser (Griesi et al., 2006). Dif-

ferences with our approach arises in the aims and in

the architecture, as the extension is essentially the

GUI of the whole knowledge management system.

While our approach exploits a lightweight, client-side

implementation of the bare ontology editing function-

alities, the Semantic Turkey system relies on server-

side processing and storing and uniﬁes the process

of editing the ontology (i.e., deﬁning terms and rela-

tions) with the creation of annotations in Web pages,

which are stored as instances of the same ontology

and manipulated adopting a Sesame database. In our

approach, the latter part is managed by the MMS

independently from the extension, and the semantic

wiki is used to create annotations. More important,

the Semantic Turkey essentially allows for the collab-

orative editing of a reference ontology, which differs

from our aim of allowing for the deﬁnition of individ-

ual ontologies that can be used collaboratively, when

needed, in a proper way.

From a cognitive and interactive perspective, the

process of creating and editing a personal ontol-

ogy with the extension presented in Section 2.3 is

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similar to the organization of regular Web book-

marks (Abrams et al., 1998). Such activity is of-

ten considered unnecessary as long as the number of

bookmarks is limited, and all the favorite URLs can

be kept together unsorted, but most Web users tends

to develop personal bookmark hierarchies (with fold-

ers and subfolders by topic) to sort their references.

The result of such operation, which usually takes only

a few minutes, is an explicit representation of the in-

terest of a person. Additionally, our browser exten-

sion can be used to express such conceptualization

in a standard language, thus, ready to be shared with

other users. It is not just social bookmarking or anno-

tation (Millen et al., 2006; Wu et al., 2006), in that the

generated ontology remains personal until parts of it

are willingly used in a collaborative setting and, thus,

shared.

4 CONCLUDING REMARKS

In this paper we have presented the ongoing work to

design a KM tool integrated with the Semantic Web

philosophy: other experiments have already been

made in this direction (De Paoli and Loregian, 2006a).

We have outlined how a semantic wiki can be in-

troduced and exploited in a knowledge management

system to effectively support explicit knowledge cre-

ation. The advantages of adopting such an approach

is to promote the publishing activity by letting users

write textual descriptions augmented with semantic

annotations, and to promote collaborative proﬁling.

We believe that adding personal annotations to

existing documents, by using personal ontologies,

should help involving users in creating new organi-

zational knowledge. Moreover, the possibility of dis-

covering new terms and relations among documents

is a rewarding additional feature.

This paper presents the integration of sample fea-

tures in an open platform — our reference KM sys-

tem — and we are currently evaluating users’ behav-

ior and responses. Our future work consist in the de-

sign and development of new features that integrate

popular tools to enhance shared and cooperative fea-

tures. For example, we are currently testing the in-

tegration of RSS feeds, so that users can edit publish

links or documents having their favorite news sources

as a reference.

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