Feature "Faceting"

Metadata In this context… What links here? [edit] Keywords/Contexts Faceting  Domain Terms Annotations {{#compound_query:Component 349545Property "-Has subobject" has a restricted application area and cannot be used as annotation property by a user.UseCaseMotivation;?HasDirection;?IsMotivating;?IsMotivatedBy;?HasReasoning Property "-Has subobject" has a restricted application area and cannot be used as annotation property by a user.Feature "Faceting";?HasDirection;?IsMotivating;?IsMotivatedBy;?HasReasoning Property "-Has subobject" has a restricted application area and cannot be used as annotation property by a user.Feature "Faceting";?HasDirection;?IsMotivating;?IsMotivatedBy;?HasReasoning name=MotivationsDeclaredOnThisPageResultItem|link=none}} Motivations [edit] [edit] Faceting ‎ (← links) DSKIMFeature ‎ (← links)

Content

About faceting

Quads forming a semantic web

A semantic web consists of quads ID: Subject → Predicate → Object.

Selections of quads forming facets

A facet represents a specific way of looking at an information universe in order to be useful for fulfilling a certain task.

A facet represents a specific section of a semantic web. A "section" is therefore a specific selection of quads.

How do we specify such a selection of quads? Answer: by specifying some parts of the quads, that is

1. the quads' subject: any or some specific by specifying them explicitly or implicitly
2. the quads' predicate: any or some specific by specifying them explicitly or implicitly
3. the quads' object: any or some specific by specifying them explicitly or implicitly

Example: NASA's use of SMW

For example NASA uses many Semantic MediaWikis, that's why we can say that one field of application for SMW is NASA. So we are interested in the question how does NASA use SMW? One way of answering this question is to explain the ontology that NASA uses on some of its SMWs. Let's call this Ontology "Field of Application NASA".

Next question is: what consitutes Ontology "Field of Application NASA"?

As mentioned above, we ask which quad patterns constitute Ontology "Field of Application NASA"? Here's the answer:

ID	Subject	Predicate	Object
	Anything	Belongs to field of application	Component 607119

That reads like this: any quad that fulfills the following pattern:

1. the subject can be any page
2. the predicate must be the property Belongs to field of application
3. the object must be Component 607119

We can visualize this:

<mermaid2 profile="Component 160431" abstraction="instinst"/>

More importantly we can let SMW prescind these facts onto their type level:

<mermaid2 profile="Component 160431" abstraction="typetype"/>

Assigning and retrieving properties

For example, we want to know all occurrences at which a property is involved in any way throughout a SMW. Conceptually SMW makes use of properties in these ways:

Assign a property value to a page by silent annotation {{#set:PROPERTY=VALUE}} or in-text annotation [[PROPERTY::VALUE]] to a page's subobject by |PROPERTY=VALUE

Retrieve a property value in #ask and #show queries by |?PROPERTY