The act of tagging is done by the person consuming
the information."
From a categorization perspective, folksonomy
and taxonomy can be placed at the two opposite
ends of categorization spectrum. The major
difference between folksonomies and taxonomies
are discussed thoroughly in (Quintarelli, 2005) and
(Shirky, 2005).
Taxonomy is a top-down approach. It is a simple
kind of ontology that provides hierarchical and
domain specific vocabulary which describes the
elements of a domain and their hierarchal
relationship. Moreover, they are created by
professional people, and require an authoritative
source.
In the contrary, folksonomy is a bottom-up
approach. It does not hold a specific vocabulary nor
does it have an explicit hierarchy. It is the result of
people own vocabulary, thus, it has no limit (i.e.
open ended), and tags are not stable nor
comprehensive. Moreover, folksonomies are
generated by people who have spent their time
exploring and interacting with the tagged resource
(Wikipedia, 2006).
2.2 Social Bookmarking Service
Social bookmarking services are server-side web
applications; where people can use these services to
save their favorite links for later retrieval. Each
bookmarked URL is accompanied by a line of text
describing it and a set of tags (aka folksonomies)
assigned by people who bookmarked the resource
(as shown in Figure 1).
Figure 1: Excerpt from the del.icio.us service showing the
tags (Blogs, internet, ... ,cool) for the URL of the article by
Jonathan J. Harris, the last bookmarker (pacoc, 3mins ago)
and the number of people who bookmarked this URL
(1494 other people).
A plethora of bookmarking services do exists
(e.g. del.icio.us, Furl, Spurl and del.irio.us);
however, del.icio.us is considered one of the largest
social bookmarking services on the Web. Since its
introduction in December 2003, it has gained
popularity over time and there have been more than
90,000 registered users using the service and over a
million unique tagged bookmarks (Menchen, 2005;
Sieck, 2005). Visitors and users of the del.icio.us
service can browse the bookmarked URLs by user,
by keywords (aka tags or folksonomies) or by a
combination of both techniques. By browsing others
bookmarks, people can learn how other people tag
their resources; thus, increasing their awareness of
the different usage of the tags. In addition, any user
can create an inbox for other users’ bookmarks, by
subscribing to the other user’s del.icio.us pages.
Ditto, users can subscribe to RSS feeds for a
particular tag, group of tags or other users.
3 RESEARCH MERITS
The FolksAnnotation tool applies an organization
scheme to people’s tags in a specific domain of
interest (i.e. teaching CSS). Thus, the folksonomy
tags in our system are modeled not as text keywords
but as RDF resources that comply to pre-defined
ontologies. This provides two benefits:
Benefit 1: While the folksonomy approach retrieves
documents by using ‘bag of words’, property-value
pairs enable more advanced search such as question
answering, reasoning as well as document retrieval.
So our approach will provide a property-value
relationship that is semantically rich and allow for
more ‘intelligent’ search such as: Search by
Difficulty, Search by Instructional level and Search
by Resource type.
Benefit 2: Typical semantic annotation tools depend
on an intermediate process called Information
Extraction (IE) to extract the main concepts from the
annotated document before relating them to the
designated ontologies. The IE process is a very
complex phase in the semantic annotation lifecycle,
and encompasses many advanced techniques from
the natural language processing domain. Moreover,
the processing time required to accomplish the IE
task is significant. So, instead of using IE process as
an intermediate phase for extracting knowledge from
documents, why not rely on people’s generated
metadata? Therefore, by using folksonomies as
knowledge artifacts in the process of semantic
annotation, we ensure that we have used a cheap and
rich source of metadata generated by people’s
collective intelligence.
4 IMPLEMENTATION
The implementation of the FolksAnnotation tool has
been previously reported in (Al-Khalifa and Davis,
2006), however, a briefly discussion about the
implemented tool and the portal that uses the
generated semantic metadata needs to be highlighted
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