Gibbs Sampling for LDAGibbs Sampling for LDA Lei Tang Department of CSE Arizona State University January 7, 2008 1 / 10 Graphical Representation α, β are fixed hyper-parameters. We need to estimate parameters θ for each document and φ for each topic. Z are latent variables. This is different from original LDA work. 2 / 10 Property of Dirichlet The expectation of Dirichlet is E(µk) = αk α0 where α0 = αk. 3 / 10 Gibbs Var
