“…Recently a number of researchers have developed provably correct algorithms for parameter estimation in latent variable models such as hidden Markov models, topic models, directed graphical models with latent variables, and so on (Hsu et al, 2009;Bailly et al, 2010;Siddiqi et al, 2010;Parikh et al, 2011;Balle et al, 2011;Arora et al, 2013;Dhillon et al, 2012;Anandkumar et al, 2012;Arora et al, 2012;Arora et al, 2013). Many of these algorithms have their roots in spectral methods such as canonical correlation analysis (CCA) (Hotelling, 1936), or higher-order tensor decompositions.…”