Abstract: A phrase extraction system combines a dictionary method, a statistical/heuristic approach, and a set of pruning steps to extract frequently occurring and interesting phrases from a corpus. The system finds the “top k” phrases in a corpus, where k is an adjustable parameter. For a time-varying corpus, the system uses historical statistics to extract new and increasingly frequent phrases. The system finds interesting phrases that occur near a set of user-designated phrases. The system uses these designated phrases as anchor phrases to identify phrases that occur near the anchor phrases. The system finds frequently occurring and interesting phrases in a time-varying corpus is changing in time, as in finding frequent phrases in an on-going, long term document feed or continuous, regular web crawl.