Hetero-labeled LDA: A partially supervised topic model with heterogeneous labels

We propose Hetero-Labeled LDA (hLLDA), a novel semi-supervised topic model, which can learn from multiple types of labels such as document labels and feature labels (i.e., heterogeneous labels), and also accommodate labels for only a subset of classes (i.e., partial labels). This addresses two major limitations in existing semi-supervised learning methods: they can incorporate only one type of domain knowledge (e.g. document labels or feature labels), and they assume that provided labels cover all the classes in the problem space. This limits their applicability in real-life situations where domain knowledge for labeling comes in different forms from different groups of domain experts and some classes may not have labels. hLLDA resolves both the label heterogeneity and label partialness problems in a unified generative process. hLLDA can leverage different forms of supervision and discover semantically coherent topics by exploiting domain knowledge mutually reinforced by different types of labels. Experiments with three document collections-Reuters, 20 Newsgroup and Delicious- validate that our model generates a better set of topics and efficiently discover additional latent topics not covered by the labels resulting in better classification and clustering accuracy than existing supervised or semi-supervised topic models. The empirical results demonstrate that learning from multiple forms of domain knowledge in a unified process creates an enhanced combined effect that is greater than a sum of multiple models learned separately with one type of supervision.