There is a long history of methods using suface-level lexical patterns for extracting relational facts from text corpora (Hearst, 1992;Brin, 1999;Agichtein and Gravano, 2000;Ravichandran and Hovy, 2002;Etzioni et al., 2004).
we obtained such latent edge labels by mining a large dependency parsed corpus of 500 million web documents and performing PCA on the result.