Inference Web
Explanations for the Semantic Web


Inference Web (IW) is a framework for explaining Semantic Web reasoning tasks by storing, exchanging, combining, abstracting, annotating, comparing and rendering proofs and proof fragments provided by reasoners embedded in Semantic Web applications and facilities. IW is expected to be flexible enough to address explanation requirements of a broad audience of Semantic Web users.

Why InferenceWeb is needed?

If users (humans and agents) are to use and integrate system answers, they must trust them. System transparency supports understanding and trust.
  • Thus, systems should be able to explain their actions, sources, and beliefs.
  • Also, if systems are hybrid, it is useful to work in an integrated yet separable manner.
These are some technical requirements for trusting system answers:
  • Provenance information - explain where source information: source name, date and author of last update, author(s) of original information, trustworthiness rating, etc.
  • Reasoning information - explain where derived information came from: the reasoner used, reasoning method, inference rules, assumptions, etc.
  • Explanation generation - provide abbreviated descriptions of the proof - may include reliance on a description of the representation language (e.g., DAML+OIL, OWL, RDF, ...), axioms capturing the semantics, rewriting rules based on axioms, other abstraction techniques, etc.
  • Distributed web-based deployment of proofs - build proofs that are portable, sharable, and combinable that may be published on multiple clients, registry is web available and potentially distributed, ...
  • Proof/explanation presentation - Presentation should have manageable (small) portions that are meaningful alone (without the context of an entire proof), users should be supported in asking for explanations and follow-up questions, users should get automatic and customized proof pruning, web browsing option, multiple formats, customizable, etc.

IW Contributions

IW makes proofs more useful for explaining queries on the Semantic Web. Trust disclosure is achieved by making proofs easy to visualize and rendering proofs using "user centered" notations. Interoperability is achieved by making proofs (and proof fragments) sharable, easy to distribute and combine, and free of unexplained reasoner-specific inference rules. Reuse is achieved by making proofs able to be annotated in addition of making them interoperable.

A list indicating how these expected IW contributions can be achieved is presented as follows.
  • OWL representation provides an interlingua for proof interchange.
  • the use of a distinct URI for each proof, whether or not the proof is also a subproof, allows the handling of all its combinations of proof fragments.
  • support for browsing multiple proofs of a single theorem provides a mechanism for comparing and analyzing distinct proofs.
  • support for explaining reasoner-specific inference mechanisms facilitates the interchange of proofs between distinct reasoning agents.
  • support for follow-up questions for a single step of proof lets people explore ONLY those portions of proofs that they care about.
  • support for browsing a single step of proof a time provides low-cost browsing of proofs. Moreover, proofs can be browsed from any of their subproofs since a subproof is a proof.
  • extensible support for rendering multiple notations (i.e., English, KIF, etc.) facilitates the understanding of proofs by distinct browser users.
  • support for adding extra information to proofs. Some pieces of extra information useful for proofs include the following:
    • identification of (authoritative) sources;
    • identification of authors of proofs;
    • identification of dates of proofs;
    • links to alternative proofs of antecedents;
    • formal description of additional properties of proofs;
    • textual (informal) description of additional properties of proofs.
Further descriptions on these IW contributions will be added to this web page soon.

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