2. The method of claim 1 , said knowledge derived from said historical conversational transcripts comprising: clustering textual segments in said historical conversational transcripts into groups of related textual segments; representing each of said groups of related textual segments by a representative syntax; forming a sequence of said representative syntax for each historical conversational transcript; finding frequently occurring subsequences from said sequence of representative syntax; and finding distinct and long frequently occurring subsequences from said frequently occurring subsequences.
2. The method of claim 1 , said knowledge derived from said historical conversational transcripts comprising: clustering textual segments in said historical conversational transcripts into groups of related textual segments; representing each of said groups of related textual segments by a representative syntax; forming a sequence of said representative syntax for each historical conversational transcript; finding frequently occurring subsequences from said sequence of representative syntax; and finding distinct and long frequently occurring subsequences from said frequently occurring subsequences. 7. The method of claim 2 , said finding distinct and long frequently occurring sub-sequences being performed by a clustering algorithm belonging to the class of leader clustering algorithm.