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Word of the day: "Negative Triples"

From: XUL Planet | Querying RDF Datasources

var target = datasource.GetTarget(karen, name, true);

You might have noticed that the GetTarget method has a third argument which is set to true above. This is used to indicate whether you want to retrieve a negative triple instead of a normal one. This is a special Mozilla-specific feature that allows an RDF statement to be false instead of true. Remember that when a piece of information is not supplied in the datasource, it means that the datasource does not know that information, not that the information is blank. For instance, if we hadn't specified Karen's name in the RDF/XML, it means that Karen's name is not known to the datasource. She may still have a name however.

A negative triple indicates that a particular statement is not true. For instance, we could add a statement that Karen's name is not 'Tracy'. Note that there is no way to actually specify this in the RDF/XML, only by directly manipulating the datasource. However, negative triples should generally be avoided. They don't really offer a lot of value and usually this kind of information is better specified in other ways.

It would be interesting to know how much these negative triples are/were actually used in Mozilla/Firefox and what for. Once there is a way to take triples away you could do incremental updates of RDF datasources if needed.

A related conversion, from #swig logs (2007-06-28 @ 14:32:36):

< TipTop> how to say that a statement is invalid, for example, without reification?

< timbl> have to either do reification properly, or you use N3 formulas.
< timbl> { Sky clor blue } a log:Falsehood.
< timbl> is the latter.

Tags: mozilla | n3 | rdf | xul

Semantic Web developers already know how to use RDF data (e.g., create timeline of the whole weblog¹) exported by SIOC RDF export tools. WordPress SIOC Import plugin demonstrates how SIOC data may be used by regular blog users (e.g., via admin user interface).

Read more and download the plugin at: WordPress SIOC Import Plugin [wiki]

The way it works is very simple: go to blog admin's interface, enter a URL of SIOC data, press "Process URL". A blog post or multiple posts are created based on this information and published on the blog.

See a screenshot below of a blog post recreated this way using SIOC data from the latest status report by John Breslin: State of the SIOC-o-sphere (#4)

Some things to keep in mind:

• There may be multiple sioc:Post objects in the source data stream. Look for "edit link" in the status reported by the plugin and find objects which were imported. If a post has comments you will probably also see some "Empty post data." messages at the bottom.
• Imported blog posts are published instantly, without using a draft. Will change this at a later stage.

"uldis, this is massively huge and massively cool. I agree, this just opens a door as big as the sky" - thanks to Mike Bergman for great feedback and testing the plugin with WordPress 2.0!

See the result of his experiment: Massively Cool (aka) T-SIOC, Object-centered Sociality (based on a post by John Breslin)

About opening the sky - this experiment acts as a demonstration² that you can use SIOC data in regular web applications and I hope it gives web developers a hint of what cool opportunities appear once you do that and start connecting different systems. And you don't need to know much RDF to do that.

For some ideas see SIOC Import Plugin - Advanced Applications [wiki].

Source SIOC RDF data do not necessarily need to come from the WordPress SIOC plugin. Any SIOC data source (SIOC Exporters contains a list of SIOC tools) which contains sioc:Post(s) is OK. A useful property of SIOC data exporters is that every page on a SIOC-enabled site (forum, bulletin board, ...) has a machine-readable representation in RDF which offers interesting possibilities compared with regular web feeds.

Note that this is an experimental, development version. Play at your own risk. Please report if you notice any bugs³.

This application uses Bengee's ARC RDF framework for PHP for parsing RDF/XML and the SIOC PHP API.

¹ Blogs in RDF: SIOC timeline
² It is a demonstration. Copying may not be so exciting by itself, and it just an example. The possiblities that open up by learning to re-use rich semantic data from social media sites are.
³ Developed on WordPress 1.5. Should work with 2.0+, let me know how it goes.

Tags: sioc | rdf | wordpress | import

The FAQ is now on the front page of Digg.com (a screenshot).
Thanks to all who participated in making it popular!

Higher visibility has also attracted some comments (11 26 at this point) which may be interesting to read and respond to.

Technorati Tags: faq | rdf | semantic web | w3c

W3C Semantic Web Frequently Asked Questions

A collection of answers to questions that you may have about the Semantic Web. Written for a general web public, with some answers going into more detail. By W3C Semantic Web Education and Outreach Interest Group (SWEO IG).

You can digg it: http://digg.com/software/Semantic_Web_FAQ_by_W3C

Technorati Tags: faq | rdf | semantic web | w3c

I presented this talk at BarCamp Ireland 3 on April 21, 2007.

There was a lot of interest and we had to move to a bigger room to accomodate all the audience (thanks to Ryan Alexander for arranging the bigger room).

PowerPoint file: "SIOC - Semantic Web for Social Media Sites" (6 Mb, PPT)
If you watch the presentation on SlideShare the hyperlinks should work as well.

Olivier Ansaldi (in comments to an earlier post):

"I really enjoyed your talk (just in case you remember, I asked you a question about microformats), it helped me get a better understanding of the semantic web. I feel more inclined to start digging in the literature that I felt before!"

If you were at the presentation and have some questions about it, please ask. Literature is one place to start, but at the same time you can try to work with the Semantic Web and RDF, and judge for yourself when and where to apply it.

Technorati Tags: barcamp | ireland | semantic web | sioc

Semantic Web and DERI Galway appear on Slashdot:

"Super-Fast RDF Search Engine Developed"

TheRegister is reporting that Irish researchers have developed a new high-speed RDF search engine capable of answering search queries with more than seven billion RDF statements in mere fractions of a second.

'The importance of this breakthrough cannot be overestimated,' said Professor Stefan Decker, director of DERI. 'These results enable us to create web search engines that really deliver answers instead of links. The technology also allows us to combine information from the web, for example the engine can list all partnerships of a company even if there is no single web page that lists all of them.'

From DERI press release [ "Semantic World Record at DERI Galway!" ]:

Andreas Harth and Aidan Hogan, key researchers on the Semantic Web Search Engine project, have been working on the project for about three years are excited about the prospects: "These were the fruits of hard labor" says Andreas Harth, "I am excited about the prospects ahead. We are currently working on realizing inferencing - making the web truly intelligent - and we have results already."