The interested reader is invited to consult (Wang, 2011) for more details on using Gibbs sampling for LDA-like models where k ∈ K, n k denotes the number of times word v is assigned to topic k, and n (cd) k denotes the number of words in document d of collection c that are assigned to topic k. By the strong law of large numbers, the average of sample parameters should converge towards the true expected value of the model parameter.
good estimates of the model parameters can be obtained averaging over the sampled values.