Archive

Archive for July, 2008

Towards Webtop

July 25th, 2008

by Jie Bao

Some of our Tetherless World researchers including me have just written a short paper to sell the idea of constructing a “webtop” using semantic technologies. In short, a webtop is a desktop on the web, that does similar jobs such as managing files, doing word processing, managing contacts, scheduling tasks, emailing, etc. Please see some examples of webtops with pretty GUIs.

Almost one decade ago, there has been hot for a while for the concept of “network computer”. At that time, a network computer means some low-end computer with limited storage and computational capacity that relying on the network to get great power. The webtop idea reminds me of network computer as they, while are different in many aspects, share the same idea of powering users with networked infrastructure. Ten years ago, this vision was tested with physical computers but largely failed, while today, with the advance of technologies, is revived by allowing users to create virtual computers that only exist on the websphere. I have many reasons to believe this time it will not only survive, but also prevail.

One reason is from my personal experience. From about two years ago, I stopped installing many software that have been with me for many years: Encarta is replaced by Wikipedia.com, Outlook is replaced by Gmail, MS Street is replaced by Google Maps, MS Word is replaced by writing in wiki, Powerpoint is replaced by online latex writing with the Beamer package, among a long list of other things. Browser is the application I stayed for more than 80% of time when I’m on my computers. There is indeed a strong need for me to organize all such online applications and data — simply bookmarking is barely a solution. I need something that can organize them, enable me quick access to them, and last but not least, pretty and neat. A webtop does exactly those things.

How semantic technologies help in providing a webtop? Actually, long before the term “ontology” getting popular, users are already creating ontologies on daily bases: email classification, creating file folder trees, grouping contacts or naming a photo as “Wedding picture at Troy”, all those efforts are creating relations between things or annotating a “meaning” to an entity. With semantic technologies, those relations and annotations can be made explicit so that data can be more easily managed and queried. For example, I may query that “find all 2005 photos of my friends”, or “show all meetings (even if they are not called meeting, such as “briefing”) in the past month”. A webtop based on semantic technologies will make such an ability universal to any application on its top.

There have been controversies about semantic web ever since the term is coined. I think this is partly because the semantic web community as a whole, failed to provide enough end-user friendly tools that can do something helpful in daily life. I wish to see more tools to help daily web activities: semantic email, semantic blog, semantic calender, semantic abstract of news (a little more than RSS), tagging files (picture, mp3,…) with taxonomy, etc. Even more important, to survive, such an application should never ask users to learn RDF or anything needs more than 3 minutes to understand. Bring such applications together, it’s a webtop. I believe something like this is one of the killer apps the community has long been waiting for.

VN:F [1.9.22_1171]
Rating: 0.0/10 (0 votes cast)
VN:F [1.9.22_1171]
Rating: 0 (from 0 votes)
Author: Categories: Uncategorized Tags:

OWL or OLD?

July 22nd, 2008

I just noticed the “OWL 2 Web Ontology Language: Requirements” document from the OWL Working Group. Interestingly, while the “W” in OWL stands for “Web”, I didn’t see any use case from web applications in the usual sense. As the leading requirements are from the need for domain knowledge bases, I would suggest the name of the new language, instead of OWL 2, to be Ontology Language of Domains (OLD) — Just kidding. OWL claims to be needed by common web users, but such users are surprisingly under-represented in the specification process. We have already seen many specially designed, highly expressive, but, narrowly applied languages in the old KR schools. Do we need to invent yet another one here, again?

Jie

VN:F [1.9.22_1171]
Rating: 0.0/10 (0 votes cast)
VN:F [1.9.22_1171]
Rating: 0 (from 0 votes)
Author: Categories: owl, Semantic Web Tags:

Human and the Semantic Web

July 16th, 2008

“The Semantic Web is mainly serving machine agents” has been dominating my mind for many years. Now human users may also want to explore the big mass of RDF data not just for debugging purpose. Semantic Web user interaction is becoming an important part of Semantic Web layer cake and research direction (see SWUI workshops) in ISWC.

As a “web of data”, the Semantic Web, boosted by Linked Data efforts, presents web users a maze of RDF graph with billions of arcs (triples). To explore the maze, below are some html browser approaches I came across:

An alternative approach is graphical browser, which seem to be more intuitive to end users. An interesting blog Large-scale RDF Graph Visualization Tools covered a handful of useful resources including something I never encountered and even links to 28 visualization software packages. Of course the list missed some RDF viz browsers such as FOAFnaut, Welkin, and self visualization. It is notable that scalability is still bugging most of the visualization approaches due to the limit of memory size: my last experience was “Otter had a hard time when processing a graph with over 10,000 nodes”.

There are still many user interaction issues beyond the browsers (e.g. search engines, semantic wiki), and a well-designed UI component is probably the key to the Killer-App of the Semantic Web.

Li Ding

VN:F [1.9.22_1171]
Rating: 0.0/10 (0 votes cast)
VN:F [1.9.22_1171]
Rating: 0 (from 0 votes)
Author: Categories: Semantic Web Tags:

What leads to interoperability? Lessons learned from Dublin Core and DOI

July 15th, 2008

Interoperability is a desired feature when people access Web content, and there is a long way towards this dream. In general, interoperability on the Web can be abstracted as many users communicating with one another to share information. Two extremes are obvious, (i) achieving a language for all at the cost of minimal information can be exchanged, and (ii) achieving a language for each pair so that such pair can maximally exchange information. These two extremes may converge when the users are homogeneous, i.e. from the same community and hosting similar information.While the simplicity and flexibility of Dublin Core (DC) have attracted many followers, they also lead to limited interoperability among DC applications. The comments in [2] made an interesting analogy: “Dublin Core applications are like snowflakes – no two are exactly the same”. For example, dc:date neither restricts the range of the value (that leaves no place of quality validation) nor offers clear enough semantics of that property (it works more like a legal document that needs lawyers’ interpretation). More researchers [1,3] criticized DC that such limited interoperability may restrict automated metadata processing and thus made DC useless.

Digital Object Identifier (DOI), on the other hand, has fast growing instance data space in the publishing industry. Unlike DC, DOI requires more agreements including (i) more mandatory properties, (ii) more restrictions on the value of properties; and (iii) a federated metadata registration mechanism. These features ensure better structured and interoperable DOI instance data.

From the above study, we may raise the following hypotheses:
1. simplicity and flexibility can lower adoption cost, but they should be carefully enforced to avoid damaging interoperability
2. restrictions (e.g. the range of property value) can ensure data quality and thus promote interoperability
3. making more information interoperated among systems is preferred to making all systems interoperating
4. interoperable metadata should support non-trivial automated data integration, such as and reference resolution.

Further readings
[1] Beall, J. (2004), “Dublin Core: an obituary“, Library HiTech News, Vol.21, No. 8, pp 40-1,
[2] Jill Hurst-Wahl (2007), “Dublin Core?”, (the comment is more interesting than the blog) access on July 15, 2008
[3] Allan Cho (2008), “Dublin Core is Dead, Long Live MODS“, access on July 15, 2008

Li Ding

VN:F [1.9.22_1171]
Rating: 0.0/10 (0 votes cast)
VN:F [1.9.22_1171]
Rating: 0 (from 0 votes)
Author: Categories: Web Science Tags: