Dirichlet–Multinomial Predictive Counts

Integrate uncertain category probabilities to predict joint counts. The Dirichlet-multinomial distribution models overdispersed categorical counts by assigning a Dirichlet prior to the underlying multinomial probabilities.

Experiment

Explore the interactive module to see how different priors and counts affect probabilities:

1. Select Concentration to Favor A. Notice how the predictive distribution shifts.
2. Change the Trials to 4 and observe the expansion of possible outcomes.
3. Switch the Count pattern to Balanced and compare the predictive probability to the fixed multinomial probability.