By the two terms: Possibility of coexistence yields concordance, and impossibility yields opposition. Ironical and teasing reversals are treated under the opposing group when their intended effect depends on an inverted relation.
By the common feature: A feature can be internal to both concepts, as with rapid traversal in running and flying, or external to their definitions, as courage in a lion and a brave person.
Good analysis also distinguishes a shared meaning from the degree of its realization. The next section introduces another division by the common feature, including familiar/common and more unusual/metaphorically distinctive kinds.