8. A system for training a ranking application to rank a plurality of help postings for display in a forum, the system comprising: a hardware processor; a ranking application, executing on the hardware processor and configured to: rank the plurality of help postings to create an initial ranking, wherein the plurality of help postings in the initial ranking is ranked by the ranking application using initial parameter values; store user interactions with the plurality of help postings presented according to the initial ranking to obtain stored interactions; and rank, using revised parameter values, the plurality of help postings to generate a revised ranking; and a simulation application, executing on the hardware processor and configured to: perform 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; analyzing the simulated rankings based on the relevance value to obtain the revised parameter values; and provide the revised parameter values to the ranking application; and calculate, 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.
8. A system for training a ranking application to rank a plurality of help postings for display in a forum, the system comprising: a hardware processor; a ranking application, executing on the hardware processor and configured to: rank the plurality of help postings to create an initial ranking, wherein the plurality of help postings in the initial ranking is ranked by the ranking application using initial parameter values; store user interactions with the plurality of help postings presented according to the initial ranking to obtain stored interactions; and rank, using revised parameter values, the plurality of help postings to generate a revised ranking; and a simulation application, executing on the hardware processor and configured to: perform 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; analyzing the simulated rankings based on the relevance value to obtain the revised parameter values; and provide the revised parameter values to the ranking application; and calculate, 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. 11. The system of claim 8 , wherein analyzing the simulated rankings comprises determining whether the simulated rankings with the revised parameter values are ordered closer to relevancy than the initial rankings.