In chapter 2, we have discussed a number of psychological results as hints to the requirements for concept representation, and the possible mechanisms for concept formation.
In chapter 3, we developed a logical representation language that meets most of the psychological requirements on concept representation, and showed that it has a well-defined semantics and is tractable.
In chapter 4 finally, we discussed MOBAL’s knowledge revision activities, which are to provide the context for concept formation.
KeywordsKnowledge Base Concept Formation Inductive Logic Programming Predicate Variable Rule Schema
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- 1.In fact, within MOBAL, the use of RDT on higher levels is currently not supported. 2 Further restrictions of the hypothesis space are defined by the predicate topology, see [Kietz and Wrobel, 1992]Google Scholar
- 4.Care must be taken, however, to avoid overinstantiating rule schemata that literally contain the target concept.Google Scholar
- 5.This way of using RDT for CLT characterization was designed by J.U. Kietz, K. Morik, and the author, and implemented by J.U. Kietz, see the acknowledgments.Google Scholar
- 6.Before these criteria are applied, CLT also checks whether the new concept has turned out to be a synonym of an existing concept.Google Scholar
- 7.Without any loss in inferential power, that is. There might be a loss of efficiency because the “compiled” one-step rule may execute faster than the two rules that replace it. Due to the cost of indexing, however, the overall effect of removing a compiled rule could also be a speedup. This is known as the utility-problem of explanation-based learning [Minton, 1990].Google Scholar
- 8.This is true only if inference depth limits are not used or set high enough.Google Scholar
- 9.The relation of this method to human concept formation certainly warrants a deeper examination, e.g. with respect to its power of predicting empirically observable psychological effects. Such studies, however, are outside the scope of this work.Google Scholar
- 10.We are thankful to R. Quinlan for making FOIL available to other researchers.Google Scholar
- 11.In [Stahl, 1993b], necessary terms according to our definition are referred to as “useful”, and useful terms according to our definition are not examined.Google Scholar
- 12.See [Stahl, 1993a] for an excellent overview of other first-order constructive induction operators.Google Scholar