Metsis et al. 2006, Pang et al. 2002, and Wang and Manning 2012show that using boolean attributes with multinomial naive Bayes works better than full counts. Binary multinomial naive Bayes is sometimes confused with another variant of naive Bayes that also use a binary representation of whether a term occurs in a document: Multivariate Bernoulli naive Bayes. The Bernoulli variant instead estimates P(w|c) as the fraction of documents that contain a term, and includes a probability for whether a term is not in a document. McCallum and Nigam (1998) and Wang and Manning (2012) show that the multivariate Bernoulli variant of naive Bayes doesn't work as well as the multinomial algorithm for sentiment or other text tasks.