11. A computer program product for determining a particular document that initiated a topic of interest in a collection of documents, each of the documents having contents and a time it was created, the computer program product comprising: a tangible storage medium readable by a computer system and storing instructions for execution by the computer system for performing a method comprising: ranking the documents in the collection based on the respective times that the documents were created; ranking the documents based on how similar their respective contents are to a topic of interest; ranking the documents based on their originality of their respective contents; ranking the documents based on an identification of a thread of each of the documents; producing a composite ranking of the documents based on the time, the contents, the originality rankings, and the thread; and determining the particular document that initiated the topic of interest from the composite ranking.
11. A computer program product for determining a particular document that initiated a topic of interest in a collection of documents, each of the documents having contents and a time it was created, the computer program product comprising: a tangible storage medium readable by a computer system and storing instructions for execution by the computer system for performing a method comprising: ranking the documents in the collection based on the respective times that the documents were created; ranking the documents based on how similar their respective contents are to a topic of interest; ranking the documents based on their originality of their respective contents; ranking the documents based on an identification of a thread of each of the documents; producing a composite ranking of the documents based on the time, the contents, the originality rankings, and the thread; and determining the particular document that initiated the topic of interest from the composite ranking. 12. The computer program product of claim 11 , wherein the collection of documents is generated by a query request.