We implemented Wallach, Mimno and McCallum's method for all the models we considered, but found that it did not improve authorship attribution accuracy in preliminary experiments.
in all our experiments we set the elements of α α α (D) and α α α (A) to min{0.1, 5/T (D) } and min{0.1, 5/T (A) }, respectively, yielding relatively sparse topic distributions, since we expect each document and author to be sufficiently  Three-dimensional Dirichlet probability density, given three prior vectors.