Specifically, we applied Hearst patterns (e.g., "NP [,] (such as | including) {N P, } * {and|or} NP") and isa patterns ("NP (is|are|was|were|being) (a|an|the) NP") to a large corpus containing 3 billion English web pages.
we obtained a term→hypernym bi-partite graph containing 40 million terms, 74 million hypernyms (i.e., category names), and 321 million edges (e.g., one example edge is "Berlin"→"city in Germany", where "Berlin" is a term and "city in Germany" is the corresponding hypernym).