Open Knowledge Base Connectivity

Action Items

This page summarizes the action items of the Open Knowledge Base Connectivity Working (OKBC) group of DARPA's High Performance Knowledge Bases (HPKB) program. The responsibility of resolving each action item is assigned to a smaller subgroup lead by a chair. The chair of the subgroup is responsible for investigating each action item in more detail and report back to the working group.

OKBC Action Items

  • 0001 OKBC compliance
  • 0002 Mechanism to query version information
  • 0003 Better support for assertions
  • 0004 Justifications
  • 0005 Annotations
  • 0006 Probabilities
  • 0007 Temporal Knowledge

    Issue No. Issue Name Version Date Raised By Subgroup Chair Others Involved Target to Resolve Resolved Version
    0001OKBC Compliance2.097-10-09SMITom RussSRI,KSL97-11-30TBD

    Many OKBC back end implementors are interested in implementing only a subset of functionality specified by OKBC. Two such examples are CLIPS back end being developed at SMI, and the plan monitoring system being developed by Jon Doyle. The task of this subgroup is to review the behavior language currently supported by OKBC, and test its adequacy in the context of CLIPS and Jon Doyle's system.

    Issue No. Issue Name Version Date Raised By Subgroup Chair Others Involved Target to Resolve Resolved Version
    0002Querying version2.097-10-09KSLJim RiceNone98-06-30TBD

    The OKBC protocol should provide a mechanism to query the version supported by an OKBC server. An OKBC server can choose to support multiple versions of the protocol, and therefore, some means should be provided to select the version of the protocol to be used in a given session.

    Issue No. Issue Name Version Date Raised By Subgroup Chair Others Involved Target to Resolve Resolved Version
    0003Assertions2.097-10-09CycorpTBDKSL,SRI98-06-30TBD

    The tell/ask interface of OKBC 2.0 protocol provides limited support for dealing with assertions. Facilities to name assertions and to assert assertions about assertions will be desirable. Variable arity n-ary predicates should be supported. Since some of the inferences in a frame representation system can be faster than in the full first order system, a hybrid knowledge model that combines the features of frame representation systems and more expressive first order systems will be desirable.

    Issue No. Issue Name Version Date Raised By Subgroup Chair Others Involved Target to Resolve Resolved Version
    0004Justifications2.097-10-09Cycorp,ISIJohn GennariISI98-06-30TBD

    When a conclusion is derived in a KB, usually some form of justification for it is maintained. The justifications can then be used to explain the result to the user. The OKBC knowledge model should include a representation of justifications and the API should provide means to access those justifications. A model of justifications is being developed by the Problem Solving Methods working group and will be transferred to the OKBC working group by John Gennari.

    Issue No. Issue Name Version Date Raised By Subgroup Chair Others Involved Target to Resolve Resolved Version
    0005Annotations2.097-10-09KSL,CycorpVinay ChaudhriKSL, Cycorp98-06-30TBD

    Annotations are arbitrary information attached to slot values, which could be comments or more structured info. Annotations can be useful for stating how the slot values were derived. Annotations cannot be easily modeled using an additional slot or a facet because they are not inherited in the same way as the slots and facets and because they do not have any meaning independent of the values to which they are attached to. The OKBC knowledge model should have a way of representing annotations and should support operations for querying them.

    Issue No. Issue Name Version Date Raised By Subgroup Chair Others Involved Target to Resolve Resolved Version
    0006Probabilities2.097-10-09KSL,CycorpRichard FikesNone98-06-30TBD

    There should be some way of manipulating probabilistic knowledge using OKBC. KSL is exploring the representation of probabilistic knowledge within OKBC 2.0.

    Issue No. Issue Name Version Date Raised By Subgroup Chair Others Involved Target to Resolve Resolved Version
    0007Temporal Knowledge2.097-10-09KSLTBDNoneTBDTBD

    Many knowledge bases associate with each assertion, a time interval for which it holds true. It remains to be seen how critical will be this requirement for HPKB applications. Therefore, this action item is tabled until indefinte time in the future.

    This page is maintained by:

    Vinay K. Chaudhri, <vinay@ai.sri.com>


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