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[Fwd: Tagging use case]

From: RaphaŽl Troncy <Raphael.Troncy@cwi.nl>
Date: Thu, 20 Jul 2006 11:39:40 +0200
Message-ID: <44BF4F5C.B806858F@cwi.nl>
To: MMSem-XG Public List <public-xg-mmsem@w3.org>
CC: George Anadiotis <G.Anadiotis@cwi.nl>

On behalf of George Anadiotis ...


Dear All

regarding the 3rd ACTION point
(ACTION: George to write up a use case around tagging [recorded in
http://www.w3.org/2006/07/10-mmsem-minutes.html#action03] )

i have received initial contribution from Thomas Franz, which i
incorporated in the following use case; all comments are welcome.

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The ever-growing success of social, tag-based resource sharing systems
such as Delicious (bookmarks), Flickr (images), Last.fm (music), YouTube
(video), Connotea (bibliographic information) etc shows that in
real-life
tagging is a very viable solution for annotating any type of resource.
Social resource sharing systems are web-based systems that allow users
to
upload their resources, and to label them with arbitrary keywords,
so-called tags.

In fact, this approach lowers the barrier of metadata annotation, since
it
requires minimal effort on behalf of annotators: there are no special
tools or complex interface that the user needs to get familiar with, and
no deep understanding of logic principles or formal semantics required -
just some standard technical expertise. This is exactly their greatest
strength: intuitiveness.

There are however certain limitations to the unstructured tagging
approach:

Let's suppose that user Mary has an account on system S1, that
specializes
in images. Mary has been using S1 for a while, so she has progressively
built a large image collection, as well as a rich vocabulary of tags
(personomy).

Another user, Sylvia, which is Mary's friend, is using a different
system,
S2, to annotate her images. At some point, Mary and Sylvia attended the
same event, and each one took some pictures with her own camera. As each
user has her reasons for choosing a preferred system, none of them would
like to change. They would like however to share the annotation work,
where possible: it can be expected that since the pictures were taken at
the same time and place, many of them will be annotated in similar way,
even by different annotators.

In the course of time Mary also becomes interested in video, starts
shooting some of her own and uploads them on system S3. If Mary has both
video and photographic material of some event, and since she has already
created a personomy on S1, she would naturally like to be able to reuse
it
on S2 as well. Furthermore, tags could provide a link between
potentially
related resources, namely those that share the same tag(s). In this
case,
if a picture and a video share the same tag, they may (within the
boundaries of word ambiguity) be about the same topic.

Currently however, achieving the the above tasks is not possible: tags
remain confined within each system's boundaries, as there is no
interoperability.

Let us imagine that a third person, John, is also using S1. In fact, he
is
also using a tag that Mary is using, T1, but in a totally different
context: as John's preferred language is different than Mary's, they
give
T1 a different meaning. Nevertheless, navigating S1 would present the
items Mary and John have tagged with T1 in the same set.

The above examples demonstrate current limitations of tag-based systems.
While tags per se only provide human interpretable semantics it is
possible to
establish machine interpretable semantics for tags. Some of the existing
efforts to better organize tags include tag bundles (hierarchy of tags),
tag clouds (visualization of a set of tags based on their frequency of
use) and tag suggestions (showing commonly used tags for resources that
have already been tagged by other users). Such mechanisms can be used to
derive taxonomic (hypernym and hyponym), synonym, and antonym relations
between tags. By relating tags with such semantic relations lightweight
ontologies may be built that can be exploited to enhance search and
browsing. Basing these lightweight ontologies on Semantic Web standards
would also promote interoperability between systems.

One emerging standard that seems to be a natural match for this setting
is
SKOS. Its intended use is to be leverage expression of thesauri,
taxonomies and folksonomies in the Semantic Web standards. There are in
fact already some results on how this process could be standardised.
Applying similar, automated, methods to personomies could transparently
produce their SKOS manifestation, which will enable existing platforms
to
integrate semantic metadata.

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Best regards
George Anadiotis
Received on Thursday, 20 July 2006 09:40:03 GMT

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