1. A method for training a ranking application to rank a plurality of help postings for display in a forum, comprising: ranking the plurality of help postings to create an initial ranking, wherein the plurality of help postings in the initial ranking are ranked by the ranking application using initial parameter values; storing user interactions with the plurality of help postings presented according to the initial ranking to obtain stored interactions; performing simulations using the stored interactions to generate revised parameter values for the ranking application, wherein performing the simulations comprises: calculating a plurality of relevance values from the stored interactions; creating a test posting; assigning, to the test posting, an initial score and a relevance value randomly selected from the plurality of relevance values to generate a test ranking; simulating user interactions with the plurality of help postings and the test posting in the test ranking to generate simulated rankings of the plurality of help postings and the test posting; and analyzing the simulated rankings based on the relevance value to obtain revised parameter values; ranking, by the ranking application using the revised parameter values, the plurality of help postings to generate a revised ranking; displaying the plurality of help postings in the forum according to the revised ranking; and calculating, from the stored interactions, an average waiting time between postings to obtain a posting interval, wherein, during simulations, a new test posting is added to the simulated rankings at each posting interval.