Help:Semantic search overview
Browsing and searching
The major benefit of Semantic MediaWiki, and the reason why we do annotations, is to simplify common tasks for users of the wiki. Those tasks include browsing, searching, and aggregating the wiki's content. Without SMW, wiki users can browse random pages, look up pages in the All pages special page, follow internal links--and little else. SMW gives visitors far more powerful tools for finding what they need in a wiki, from the simple factbox at the bottom of an article to the powerful technique of searching by inline queries.
Typically, the factbox displays all annotations in some article near the end of the article. This shows users what Semantic MediaWiki actually "understood" when reading the annotations. Some annotations might be hidden by using alternate text, and sometimes Semantic MediaWiki cannot interpret a user's annotation (e.g. an attribute that expects numbers has a text value).
The factbox displays all properties in one place, in alphabetical order by their name, with no discrimination among properties as to their assigned type. Each property name in the factbox is a link to its article (if any) in the Property namespace, so that users can quickly obtain further information about their usage. All this helps editors spot errors and improve the quality of the wiki.
The factbox provides more features for browsing the wiki. In most cases, Page-type annotations in the factbox provide links to all involved articles, and an icon that links to a simple inverse search. For example, if an article (say, Isaac) contains the annotation [[son of::Abraham]] then its factbox links to a search that lists all articles with a similar annotation (i.e. both of Isaac's named parents). The factbox also has an icon that links to a simple browser of the semantics in the wiki. This browser shows relations on other pages to this article as well as its own facts.
(Note: An advanced browser for the wiki knowledgebase and other ontology based navigation features are available along with the Halo Extension.) The administration is actively researching this and all other spinoff extensions of Semantic MediaWiki. All editors are invited to follow the above link and investigate Halo for themselves and make recommendations at the Coffeehouse.
For properties that support units of measurement, the factbox displays converted values in different common units, and specifically those units that the property's definition allows for display. This feature is closely related to the ability to create custom units.
Finally, the factbox contains a link to retrieve the factbox contents in the machine-readable RDF format.
Each SMW installation can configure the factbox to display in every article, or only in articles that contain annotations, or not to display at all.
In some cases, such as for the Property:Coordinates, the factbox also shows links to external services. For Property:Coordinates, these are online mapping services where aerial images and maps of the chosen location can be found. The links that should be provided for each attribute (if any) can be customized by editors. See Help:Semantic service links for details.
Semantic search provides the most powerful way for searching information in Semantic MediaWiki. It can be used via the Special:Ask page (labeled as "Semantic Search") or by adding inline queries to articles. For more information, see Help:Semantic search.
Inline queries using <ask>
Editors employ the syntax of semantic search to formulate a question in the source of an article. The rendered article then shows the result to this query, so that every user can benefit from the semantic capabilities without actually learning the wiki's query syntax. For a full description of this feature, see Help:Inline queries.
In addition to inline queries, Semantic MediaWiki offers a number of simple ways for accessing the semantic contents of the wiki. First of all, the existing relations and attributes, as well as their current usage can be monitored via the pages Special:Properties, Special:UnusedProperties, and Special:WantedProperties. Special:Types lists the available datatypes for properties.
These approaches search for semantic properties of articles. To simply see existing articles about attributes, relations, categories, and types, even if unused or garbled, use Special:Allpages to display all articles in these namespaces.
External tool support
Semantic MediaWiki makes semantic knowledge available to external tools via its RDF export, and it therefore is possible to write external tools that implement further advanced browsing and searching functionality. Currently, many tools that work on RDF output are not very user-friendly yet, but the supplied data format RDF is easy to process and could be integrated in much more elaborate web or desktop applications. For more information, there is a list of tools that have been tested with Semantic MediaWiki so far. Feel free to add your own tool there as well.
This page is part of the CreationWiki Semantic MediaWiki Help series - prepared to assist editors in becoming productive members of the CreationWiki community. Browse the Table of Contents