Context in ontologies and databases

  • For selecting knowledge to consider, its conditions of activation and limits of validity at a given time

  • For giving the relevant pieces of information necessary to the task at hand

  • Example:

    The concept of water is viewed differently by a thirsty person, a plumber, a chemist, and a painter.

  • In the context interchange approach (Goh et al., 1995),a context mediator compares the contexts of the source and the receiver to detect any conflict.

  • In Context-SQL (Sciore et al., 1992), an extension to SQL (C-SQL) allows the receivers' import context to be dynamically instantiated in a query.

  • Context is an ontology of the involved design concepts and of the topological relations between them.

  • Context of a component:

    - captures its role during the assembly,
    - describes the knowledge required,
    - specifies its input and output requirements, and
    - encapsulates its behavior for reuse.

  • For Wiederhold and Jannink (1999):
    Contexts are units of encapsulation for ontologies

  • Therefore,

    - Ontology: a set of terms and their relationships - Context: the extent of validity for an ontology - Articulation: an intersection of two ontologies which establishes a new context

  • The Oracle7 ConText Option (1996) proposes context-based document summaries and conveys their key themes without human intervention