8. The computer-implemented method of claim 1 , the method further comprising determining one or more breaking topics.
8. The computer-implemented method of claim 1 , the method further comprising determining one or more breaking topics. 9. The computer-implemented method of claim 8 wherein determining one or more breaking topics is based on a comparison of (i) the revised set of topics for the second level of popularity, calculated at a first time period, and (ii) a revised set of topics for the second level of popularity calculated at a second time period.