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Encoding Information

SWM represents information conceptually in form of an labeled directed acyclic graph where …
…nodes represent pages or subobjects
…edges represent relationshiphs between pages, literals and subobjects

Consider the following example:

Matthias Frank is an employee of the FZI Research Center for Information Technology working in the BigGIS project. BigGIS is a research project started at April 2016 and dealing with real-time big data and semantic technologies.

How could we represent this excerpt of a universe of discourse in form of an conceptual graph?

Example A representation of the above example as conceptual graph

In this conceptual graph, we distinguish between …

  • individuals — represented as blue boxes
  • relationships — represented as yellow boxes
  • literals — represented as red box

We also defined the direction of a relation to indicate the real-world semantics between their vertices.

How can we represent such information in SMW, ie., how can we transform the previous conceptual representation into an SWM’s datamodel compliant graph?

Example A Semantic MediaWiki-based representation of the previous example

The central elements in SMW’s data model are pages adhering to distinct, pre-defined namespaces in order to obtain their formal, model-theoretic semantics needed for representing the real-world semantics of the universe of discourse accordingly.

Factual knowledge is editied on the wiki pages of each element, e.g. Matthias Frank or BigGIS.

Considering the above graph,

  • Matthias Frank, BigGIS, FZI, and Real-Time Big Data are pages in the main namespace
  • member_of, start_date, works_at and has_topic are wiki pages in the Property namespace
  • start_date contains a datatype annotation on its wikipage declaring the objects of statements in which start_date participates as literal of datatype Date; hence SMW treats it as a specific value (with certain lexical structure and restrictions) rather than a wiki page.
  • April 2016 this is a literal without a separate wiki page

Thus, datatypes in property declarations control input and output (and some more things)

  • Output
    • [[member_of::BigGIS]] appears as link
    • [[start_date::April 2016]] appears as date
  • Input
    • [[my property::1000]] vs. [[my property::1,000]]
      • Different value if my property has type Wikipage
      • Same value if my property has type Number
    • In particular useful when used in conjunction with PageForms to limit permitted values of an input element according to an property’s datatype.

Tip

Task:
a) Take the previous graph and determine what information (annotations) are encoded on which pages.
b) Also list all the pages that are needed for representing the above graph in SMW.