## The Complexity of Theory Revision (1998)

Venue: | In Proceedings of IJCAI-95 |

Citations: | 15 - 5 self |

### BibTeX

@INPROCEEDINGS{Greiner98thecomplexity,

author = {Russell Greiner},

title = {The Complexity of Theory Revision},

booktitle = {In Proceedings of IJCAI-95},

year = {1998},

pages = {175--217},

publisher = {Morgan Kaufmann}

}

### OpenURL

### Abstract

A knowledge-based system uses its database (a.k.a. its "theory") to produce answers to the queries it receives. Unfortunately, these answers may be incorrect if the underlying theory is faulty. Standard "theory revision" systems use a given set of "labeled queries" (each a query paired with its correct answer) to transform the given theory, by adding and/or deleting either rules and/or antecedents, into a related theory that is as accurate as possible. After formally defining the theory revision task, this paper provides both sample and computational complexity bounds for this process. It first specifies the number of labeled queries necessary to identify a revised theory whose error is close to minimal with high probability. It then considers the computational complexity of finding this best theory, and proves that, unless P = NP , no polynomial time algorithm can identify this near-optimal revision, even given the exact distribution of queries, except in certain simple situation. It ...