The categories used in our experiments were automatically mined from the web, by following existing work (Hearst, 1992, Pantel andRavichandran 2004;Snow et al., 2005;Talukdar et al., 2008;Zhang et al., 2011).
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.