14. The system as described in claim 8 , wherein the combining of the at least the first appraisal value and the second appraisal value of the search phrase includes weight and sum at least the first appraisal value and the second appraisal value of the search phrase.
8. A system for recommending search phrases, comprising at least one processor configured to: obtain one or more subject terms and one or more descriptive terms relating to the one or more subject terms from title information of information published by publishers; combine at least some of the one or more subject terms with at least some of the one or more descriptive terms to form a set of one or more search phrases; calculate a first appraisal value for a search phrase among the set of one or more search phrases, the calculating of the first appraisal value comprising multiplying term frequency of the search phrase with an inverse document frequency of the search phrase; determine a second appraisal value of the search phrase, the determining of the second appraisal value comprising: calculate an inverse class frequency of the search phrase within a designated category, wherein the inverse class frequency is regarded as the second appraisal value; calculate a third appraisal value of the search phrase, comprising to: calculate a first probability that a first term associated with a search phrase that appears in the published information; calculate a second probability that the first term appears jointly with a second term in the search phrase associated with the published information; and combine the first probability and the second probability to obtain the third appraisal value; combine at least the first appraisal value, the second appraisal value, and the third appraisal value of the search phrase to obtain a publisher recommendation appraisal value for the search phrase; and select a recommended phrase among the set of one or more search phrases based at least in part on a set of one or more corresponding publisher recommendation appraisal values for the set of one or more search phrases; and a memory coupled to the at least one processor and configured to provide the at least one processor with instructions.