First, we relax the assumption made by most previous work (Zhu and Ghahramani, 2002;Baluja et al., 2008;Subramanya and Bilmes, 2008;Subramanya and Bilmes, 2009;Subramanya et al., 2010;Das and Petrov, 2011;Das and Smith, 2011) that the 1 norm of the masses assigned to the labels for a given vertex must be 1.
in our framework, the label distribution at each vertex is unnormalized-the only constraint we put on the vertices' vectors is that they must be nonnegative.