26. A system for detecting new topics in a plurality of interactions, given a plurality of known topics, the system comprising: a processor; and memory, wherein the memory has stored thereon instructions that, when executed by the processor, cause the processor to: extract a plurality of fragments from the plurality of interactions, the plurality of interactions occurring over a particular time period, each fragment of the plurality of fragments comprising one or more words; initialize a collection of detected new fragments to an empty collection; compute a similarity between each fragment and each of the known topics, each of the known topics comprising a template fragment comprising one or more template words, the similarity between a fragment of the fragments and a topic of the known topics being computed based on the one or more words of the fragment and the one or more template words of the template fragment of the topic; identify, for each fragment, a corresponding topic having a highest similarity; add a fragment of the fragments to the collection of detected new fragments in response to the similarity between the fragment and the corresponding topic having the highest similarity is less than a threshold value; extract one or more new topics from the collection of detected new fragments; and return a collection of the one or more new topics detected in the plurality of interactions, the collection comprising indications of frequencies at which the one or more new topics occur in the plurality of interactions during the particular time period.
26. A system for detecting new topics in a plurality of interactions, given a plurality of known topics, the system comprising: a processor; and memory, wherein the memory has stored thereon instructions that, when executed by the processor, cause the processor to: extract a plurality of fragments from the plurality of interactions, the plurality of interactions occurring over a particular time period, each fragment of the plurality of fragments comprising one or more words; initialize a collection of detected new fragments to an empty collection; compute a similarity between each fragment and each of the known topics, each of the known topics comprising a template fragment comprising one or more template words, the similarity between a fragment of the fragments and a topic of the known topics being computed based on the one or more words of the fragment and the one or more template words of the template fragment of the topic; identify, for each fragment, a corresponding topic having a highest similarity; add a fragment of the fragments to the collection of detected new fragments in response to the similarity between the fragment and the corresponding topic having the highest similarity is less than a threshold value; extract one or more new topics from the collection of detected new fragments; and return a collection of the one or more new topics detected in the plurality of interactions, the collection comprising indications of frequencies at which the one or more new topics occur in the plurality of interactions during the particular time period. 27. The system of claim 26 , wherein the memory further has stored thereon instructions that, when executed by the processor, cause the processor to: receive a request to stop tracking a blacklisted topic; add the blacklisted topic to a collection of blacklisted topics; and compute a similarity between each fragment and each of the blacklisted topics, wherein the instructions to compute the similarity between each fragment and each of the known topics are only executed in response to the similarity of the fragment to any blacklisted topic being less than a blacklist threshold value.