The K&H dataset contains only instances from three domains and is imbalanced between the number of instances across domains and relation types.
given two word pairs, (w 1 , w 2 ) and (w 3 , w 4 ), if w 1 is lexically similar to w 3 and w 2 to w 4 (i.e., are pair-wise similar) then the pairs are said to have the same semantic relation.