Understanding a part of JRip rule-based classifier output

Question

I've run JRip and i got a set of rules in this form:

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                                                                      V
(something >= 0.076) and (someotherthing >= 0.013) => class=1 (944.0/42.0)

I'm tring to understand what the numbers 944.0 and 42.0 mean. Almost sure 944.0 is the number of instances covered by the rule, but I can't really undestand the second one.

Answer 1

The result (A/B) indicates:

• A: the weight of all instances supported by the rule
• B: the weight of all instances misclassified
• (A - B): the weight of all instances correctly classified, thus A > B

Note that, if you are not using weights, each instance has weight 1, and the value represents the number of instances.

Answer 2

the 2nd number is number of instances misclassified by rule