- Ankur P. Parikh, Le Song, E. Xing. 2012. Supplemental for Spectral Algorithm For Latent Tree Graphical Models. Abstract: The latent tree structure learned by the algorithm by [1] is shown in Figure 1. The blue nodes are hidden nodes and the red nodes are observed. Note how integrating out some of these hidden nodes could lead to very large cliques. Thus it is not surprising why both our spectral method and EM perform better than Chow Liu. The Chow Liu Tree is shown in Figure 1. Note how it is forced to pick some of the observed variables as hubs even if latent variables may be more natural.
