We present an unsupervised learning algorithm that mines large text corpora for patterns that express implicit semantic relations. For a given input word pair X : Y with some unspecified semantic relations, the corresponding output list of patterns P1 , , Pm is ranked according to how well each pattern Pi expresses the relations between X and Y . For example, given X = ostrich and Y = bird , the two highest ranking output patterns are “X is the largest Y” and “Y such as the X”.
