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; display the plurality of help postings in the forum according to the initial ranking; store user interactions with the plurality of help postings to obtain stored interactions; rank, using revised parameter values, the plurality of help postings to generate a revised ranking; and display the plurality of help postings in the forum according to the 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; determining a probability that a user will view the plurality of help postings and the test posting in the test ranking; generate, based on the probability, 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.
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; display the plurality of help postings in the forum according to the initial ranking; store user interactions with the plurality of help postings to obtain stored interactions; rank, using revised parameter values, the plurality of help postings to generate a revised ranking; and display the plurality of help postings in the forum according to the 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; determining a probability that a user will view the plurality of help postings and the test posting in the test ranking; generate, based on the probability, 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. 13. The system of claim 8 , wherein the ranking the plurality of help postings and determining the probability uses the same ranking algorithm, wherein the ranking algorithm assigns a score to each of the plurality of help postings and test posting, and wherein the score is based on a popularity value and a seed value.