ILP :- Just Trie It

Rui Camacho, Nuno A. Fonseca, Ricardo Rocha and Vítor Santos Costa

June 2007

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Abstract

Despite the considerable success of Inductive Logic Programming, deployed ILP systems still have efficiency problems when applied to complex problems. Several techniques have been proposed to address the efficiency issue. Such proposals include query transformations, query packs, lazy evaluation and parallel execution of ILP systems, to mention just a few.
We propose a novel technique to improve the execution time of an ILP system that avoids the procedure of deducing each example to evaluate each constructed clause. The technique takes advantage of the two stage procedure of Mode Directed Inverse Entailment (MDIE) systems. In the first stage of a MDIE system, where the bottom clause is constructed, we store not only the bottom clause but also valuable additional information. The information stored is sufficient to evaluate the clauses constructed in the second stage without the need for a theorem prover. We used a data structure called Trie to efficiently store all bottom clauses produced using all examples (positive and negative) as seeds.
The technique was implemented and evaluated in two well known data sets from the ILP literature. The results are promising both in terms of execution time and accuracy.

Bibtex

@InProceedings{camacho-ilp07-wip,
  author =    {R. Camacho and N. A. Fonseca and R. Rocha and V. Santos Costa},
  title =     {{ILP :- Just Trie It}},
  booktitle = {Work-in-Progress Proceedings of the 17th International Conference on Inductive 
               Logic Programming (ILP 2007)},
  month =     {June},
  year =      {2007},
  address =   {Corvallis, Oregon, USA},
}

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