While I agree that it can be unstable (inference can get stuck in local maxima), latent variable models like LDA can be used to rigorously evaluate textual cate

While I agree that it can be unstable (inference can get stuck in local maxima), latent variable models like LDA can be used to rigorously evaluate textual categories (e.g. journal articles). We take for granted that the categories we set are "useful", in some sense, so it's interesting to see that quantitatively questioned. e.g.: http://www.pnas.org/content/early/2010/11/12/1013452107.abstract http://www.pnas.org/content/early/2010/11/12/1013452107.abst... Also, for the curious, original paper on LDA: http://www.cs.princeton.edu/~blei/papers/BleiNgJordan2003.pdf http://www.cs.princeton.edu/~blei/papers/BleiNgJordan2003.pd....