The generative process starts by drawing each latent polarity value z w from a three-dimensional Dirichlet prior, parameterized by α w = (1, 1, 1): If the word is uncontroversial, 3 we spur this prior somewhat using the number of lexica in which the word appears c(w).
we add c(w) to the parameter for the sentiment associated with that word in the lexica, e.g., α SUPERB = (1 + c(SUPERB), 1, 1).