Semantic MediaWiki (SMW) is a a single extension to the ever-popular MediaWiki that instantly adds semantic web capabilities to your wiki pages. That means that you can annotate important data in the text, relate it with an ontology, format it so it looks pretty on the screen, and share it across pages or even applications. That’s a lot to digest from just one extension, so I’ll highlight some common uses.
Effortless Wiki Gardening
Once you’ve annotated some text in your wiki, you can then slice it any way you wish. That means you can reuse bits of text rather than duplicating them, combine them in unique ways, and order them according to some logic. An ontology creates inherent relationships between things, and SMW let’s you use that to create inherent relationships between your articles.
Ad Hoc Templates
Most of the wikis I’ve dealt with require coding in the wikis native language to create custom macros or page templates. For me that pretty much kills any urge to templatize at all — that’s just more code to keep track of, debug, and tweak. With Semantic MediaWiki you can create a custom data type that users “instantiate” and fill in with data. That way you can encourage a standard set of properties much like an LDAP schema. The presentation is separate from the data, so the users are shielded from having to master the ins and outs of wiki formatting or HTML. The cherry on top is that the template itself is created just like a normal wiki page!
Queries Without the Database
Once you have your wiki filled with annotated data you can include that data in any other part of the wiki. The closest comparison I can make is to how images are included within articles. Once you’ve uploaded an image you can then reference that image (or in some cases various sized thumbnails) in any number of other pages without re-uploading. An example borrowed from the SMW site is that of the population of California. If you used that bit of information in several pages, you’d have to update each page whenever somebody was born or died. That’s a slightly contrived example, so here’s something more practical: If you kept your company’s personnel records as wiki pages you could create a report page that shows the complete list of employees, followed by who does or does not take part in the health plan.
Why You Care
Wikis are the dominant form of information sharing within technology-savvy groups. That’s due in large part to the ease with which information can be added to them. However, without structure and careful organization information can easily be lost within them. Search features help, but only if you know what you’re looking for. That’s the point where flat text simplicity intersects the utility of structured data. That’s the brink where information becomes knowledge.