Editing Category:Theatre (section)

== Approaches to Semantic Web applications ==

=== Mining ===

There are essentially two types of SemWeb applications, mining and intentional semantic development. One technique in mining is "scraping" to parse presumably reliable HTML pages. Many citizen projects use this technique to extract public data from recalcitrant government sources, for example, [http://www.theyworkforyou.com They Work for You]. Mash ups are related, sites like [http://www.housingmaps.com Housing Maps] combine data from disparate sources into one useful interface. However, scraping can be easily foiled by obfuscating low level structure, intentionally or not.

Another mining approach involves scraping human oriented text. [http://www.opencalais.com Open Calais] is a infrastructure example of this. [http://healthbase.netbase.com Health Base] is an end user application. These sites use patterns in human text to try to derive statements. This technique is easily foiled leading to incorrect observations.

=== Intentional markup ===

Intentional semantic development involves explicit markup of text items. Most HTML documents today contain only text and links. Semantically marked up documents have explicit annotations about data objects, indicating them as entities such as people, places, dates, and so on. Relations (links) have explicit meanings.

In [http://www.foaf-project.org/ FOAF], we can indicate "me" links  on our home page that indicate another representation of ourselves. We can indicate links to friends, business associates, and organizations. It quickly becomes apparent that decentralized Facebook sites will be enabled, where individuals can publish their information wherever they like, using whatever licenses they like, and sites like Facebook can provide their own views of these webs of data referring to embedded licenses like [http://wiki.creativecommons.org/CcREL ccRel].

Standard RSS and Atom syndicated feeds are also gaining rich data, including geo location, that allow third party sites to create views based on distributed data.

Using RDFa and Microformats, annotations are added to regular HTML that give them semantic meaning. A person's information can be marked up with hCard, allowing you to "right click" on a web page to add that person to your address book. Similar formats exist for locations and events. 

Google, Yahoo and others use these formats to make their results more reliable. Without them, information is guessed from overall content on a page. So if you searched for "frames," looking for picture frames, you would be likely to find a page that referred to "frames" in its navigation. RDFa and Microformats allow more reliable markup of subjects, allowing meta directories to embed reviews from any cooperating site rather than trying to do everything themselves - because these reviews link back to the originating site, it's a "win win win" situation, for the meta directory, originating site, and end user, with richer, less biased results when a critical mass is reached.

The heavyweight options are systems such as RDF and Topic Maps. They provide a complex interlinked way to describe arbitrary data. Today they are only used for specific projects, but as their use grows we can expect the web to become more interlinked, allowing an endless assemblage of information using the best references.

One way to 'intentionally' create semantic data is Semantic Mediawiki.

{{Next|Semantic Mediawiki and the Semantic Web}}

[[Category:SemWeb]]