Topic Modeling for Marketing Insights, Latent Dirichlet Allocation, and Structural Topic Models
摘要
You move from labeling documents to discovering themes without labels. The chapter demystifies latent Dirichlet allocation (LDA) (Dirichlet priors, document-topic \(\theta \) and topic-word \(\phi \) , Gibbs sampling), then gets practical: plain LDA in seededlda, seeded LDA (with a dictionary + optional residual topics), and sentence-based LDA (sequential, topic continuity via gamma). You visualize with LDAvis and then level up to STM, which bakes in metadata: prevalence (which docs talk about a topic) and content (how vocabulary within a topic shifts by covariate like Brand). You estimate effects (estimateEffect), plot brand differences, time trends, interactions, and topic correlations. Finally, you cover choosing K with stm::searchK and ldatuning, and tie everything to marketing use cases (feature pain points, seasonality, brand comparisons, content strategy).