1. A method for recommending search phrases, comprising: obtaining 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; combining 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; calculating 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; determining a second appraisal value of the search phrase, the determining of the second appraisal value comprising: calculating an inverse class frequency of the search phrase within a designated category, wherein the inverse class frequency is regarded as the second appraisal value; calculating a third appraisal value of the search phrase, comprising: calculating a first probability that a first term appears in a search phrase associated with the published information; calculating a second probability that the first term appears jointly with a second term in the search phrase associated with the published information; and combining the first probability and the second probability to obtain the third appraisal value; combining 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 selecting 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.
1. A method for recommending search phrases, comprising: obtaining 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; combining 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; calculating 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; determining a second appraisal value of the search phrase, the determining of the second appraisal value comprising: calculating an inverse class frequency of the search phrase within a designated category, wherein the inverse class frequency is regarded as the second appraisal value; calculating a third appraisal value of the search phrase, comprising: calculating a first probability that a first term appears in a search phrase associated with the published information; calculating a second probability that the first term appears jointly with a second term in the search phrase associated with the published information; and combining the first probability and the second probability to obtain the third appraisal value; combining 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 selecting 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. 16. The method as described in claim 1 , wherein the search phrase includes a descriptive term, a subject term, or a combination thereof.