The Tetherless World Weblog

Sharon Myrtle Paradesi of the DIG group, MIT, has helped us to generate a tag cloud for ISWC 2010. The input is abstracts of papers in the proceedings (i.e., research track, in-use track, doctor consortium track, and invited talks) and poster/demo proceedings. While I don’t know the full details of Sharon’s techniques, she applied a set of NLP algorithms (e.g., stemming, casing, and stop word removal, etc.) to make the cloud.

As one may expect, Ontology, Semantic, Data, Query and Web are most visible. OWL, RDF and SPARQL are in comparable size, while RIF is not seen. Also notable to mention that MediaWiki is in the cloud (confession: I’m biased).

It would be interesting to compare the evolution of such word clouds of ISWC year by year – ISWC actually has 8 years of metadata since 2003.  I hope Sharon and I will find time to do it sometime in the future.

This is another visualization using Datapress
It shows talks at the main conference of ISWC 2010.

• talks - Google Docs

I attended a seminar at MIT last Friday (for this year, I’m a part-time member of the DIG group there). Edward Benson gave an impressive demo on Datapress, an extension of WordPress that can enable non-geeks to import and visualize data in their blogs.

Since our TW blog is based on WordPress, I installed the extension and began to try. The installation was surprisingly smooth, just a few clicks and it’s done in 30 seconds!

The first thing I want to try is to visualize the ISWC 2010 dataset I recently built. Since Datapress does not yet support importing from RDF, I created a spreadsheet using a SPARQL query in TopBraid Composer:

SELECT distinct ?l ?lat ?long
WHERE {
?s swc:isSubEventOf iswc2010:research-track .
?s swc:isSuperEventOf ?p .
?p swc:hasRelatedDocument ?d .
?d foaf:maker ?m.
?m swrc:affiliation ?o.
?o rdfs:label ?l .
?o foaf:based_near ?b .
?b geo:lat ?lat.
?b geo:long ?long .
}

There are some minor format requirements (I didn’t get it right in the first try -Ted helped me to identify the problem)
* the first line of the spreadsheet should be headers, and the “key” line should have “{{label}}”
* To show on a map, coordinates should be shown as Lat,Lng. Hence, I need to combine the last two columns into one, separated with a comma.

The next step is to upload it to Google Docs, and share it as a public document (can be viewed here)

Then, I can go back to the blog post that I’m writing, click a button on Datapress toolbar in the editing interface, add the data by giving it the URL to the Google Docs spreadsheet, and select Map visualization. The process is very user friendly.

You can add multiple visualizations to one post. This is a very handy way to generate visualization using Exhibit. Actually, I have thought about visualizing ISWC data using Exhibit, but didn’t get time (or too lazy) to program. Datapress saved me.

Ted will give the presentation about Datapress at ISWC next week. Don’t miss it if you will also be at Shanghai!

(The map shows locations of research track authors at ISWC 2010.)

• datapress - Google Docs

We’re pleased to announce the OWL 2 Reference Card [1]. The Card is meant to be a “cheat sheet” of OWL 2 features printable on a single piece of paper (on both sides). It is based on the OWL 2 Quick Reference Guide [1], which is now a Proposed Recommendation [2] in the OWL 2 Web Ontology Language document set.

Background: OWL 2 [4] is an extension to OWL 1 with a few new functionalities. Some of the new features are syntactic sugar (e.g., disjoint union of classes) while others offer new expressivity, including:

* keys;
* property chains;
* richer datatypes, data ranges;
* qualified cardinality restrictions;
* asymmetric, reflexive, and disjoint properties; and
* enhanced annotation capabilities

Comments and suggestions to the Card are welcome (please send to public-owl-comments@w3.org)

[1] http://www.w3.org/2007/OWL/refcard

[2] http://www.w3.org/2007/OWL/wiki/Quick_Reference_Guide

[3] http://www.w3.org/TR/2009/PR-owl2-quick-reference-20090922/

[4] http://www.w3.org/TR/owl2-overview/

Jie Bao

Just saw Jim’s post on What is the Semantic Web really all about?

I have been wondering about this problem too. What is Semantic Web? Yesterday I have asked a question “Why few (or none?) Web 2.0 sites provide hierarchical tagging?” on LinkedIn and get some pretty good answers:

http://www.linkedin.com/answers?viewQuestion=&questionID=496785&askerID=14212719

For your convenience, I attached my LinkedIn post at the end of this blog.

There are two things in the answers that draw my attention:
* Many do _not_ believe tags, or even hierarchical tags, are semantic; “semantics” means RDF or triples at least to them;
* Some believe that even implementing a hierarchical tagging system is not easy in engineering or social aspects.

I think these two beliefs, among many other reasons, may explain in part why the “Semantic Web” is still far from a reality. The first is about the overestimation of what is “semantics”: triple is one way to express semantics, but it is a question that whether it is _the_ way. The second is about the underestimation of “Web”-scale: realizing a knowledge system, even if is conceptually “simple”,  on the Web can lead to serious scalability problems, both for machine (can you make <1s response for all queries?) and for people (on changing their way of thinking).

Here is what I believe about “semantic web” (note no-capitalization). First, it is not necessarily “the Semantic Web” (just like there is no “the Mobile Web”), as defined by W3C standards or the layered cake model. Semantics is a way of organizing things, RDF and OWL are some ways to express it, but other ways should be encouraged too and sometime work better. Second, tools and services should be “web-ish”, something like a semanticized version of youtube or gmail; after all, “web users” are rarely a bioinformatician or can master a Java-based ontology editor.  Third, start deployment with very very basic semantics like trees (yeah, I know some will protest) and sameAs, but do it in a very very efficient way – if we can’t even come up with a Web-efficient tree reasoner, then how realistic we can come up with a Web-efficient RDF or OWL reasoner?

Now I’m prepared to dodge tomatoes :D

by Jie Bao

===============

My original post on LinkedIn (reorganized a bit)

Why few (or none?) Web 2.0 sites provide hierarchical tagging?

Gmail label and delicious tagging are flat, which is troublesome all the time for me. I have to add (unnecessarily) many tags even if they can be easily inferred. I didn’t find an alternative that allows me to organize my tags in a tree or network. Is there any technical or marketing reason?

People have been talking about semantic web a for a while and are looking for a killer app. It’s apparent that hierarchical tagging is semantic, is in high demand, and is relatively easy to do. Why there is none in popular sites?

PS 1: Let me clarify some situations when hierarchical tagging will save me a lot of time: recently I’m reading a book of Qian Mu, a historian, and tagging my notes on delicious with tags “qianmu“; I also want all those notes be tagged with “history“, but I have to always add both “qianmu” and “history”.

Sometimes I want more than one tags to be inferred. For example, when I add “wuxu” (the year of 1898), I want tags “qing“, “china” and “reform” to be added. You will find how trouble it is to add all 4 tags together when you have about 10 notes on “wuxu”.

In another example, I want to share my tags in both Chinese and English. If I can define two subclass relations between two tags, each in a different language, I will not have to always add the both tags.

Now I have about 1000 tags on delicious. I’m really really in despair need for a hierarchy. I’m willing to pay delicious $100 for such a service.

PS 2: Further clarification: I don’t believe I will need a tagging system that always requires me to pick up terms from a tree, DAG, or a network. I can still freely add tags. But I need some way to clean up my tags from time to time, and organize them. It is just like how i clean up my “download” folder: put them into different folders, and if a folder is too big make some subfolders.