In practice, a class label is deemed more relevant for an instance if the pair is extracted more frequently and by multiple patterns, with the scoring formula: where F req(C, I) is the frequency of extraction of C for the instance I, and Size({P attern(C)}) is the number of unique patterns extracting the class label C for the instance I.
class labels preceding endangered animals already capture the notion of animals or species (first and third labels), or that they are endangered (second label).