This article presents a heuristic, attribute-based, noise-tolerant dat
a mining program, HCV (Version 2.0), based on the newly-developed exte
nsion matrix approach. By dividing the positive examples (PE) of a spe
cific class in a given example set into intersecting groups and adopti
ng a set of strategies to find a heuristic conjunctive formula in each
group which covers all the group's positive examples and none of the
negative examples (NE), the HCV induction algorithm adopted in the HCV
(Version 2.0) software finds a description formula in the form of var
iable-valued logic for PE against NE in low-order polynomial time at i
nduction time. In addition to the HCV induction algorithm, this articl
e also outlines some of the techniques for noise handling and discreti
zation of numerical domains developed and implemented in the HCV (Vers
ion 2.0) software, and provides a performance comparison of HCV (Versi
on 2.0) with other data mining algorithms ID3, C4.5, C4.5rules, and Ne
wID in noisy and continuous domains. The empirical comparison shows th
at the rules generated by HCV (Version 2.0) are more compact than the
decision trees or rules produced by ID3-like algorithms, and HCV's pre
dicative accuracy is competitive with ID3-like algorithms.