Given twelve different sentences, same language, with the same meaning
you are to find and report that meaning.  What is that process software called?

If you get an answer from a proper GA Researcher, you can probably
ignore this comment.

But in case no-one offers a definite answer, you might like to look at
Google Answers Question ID: 502508 "What software ... allow searching
text for themes, ideas, and concepts?" to see if the answer by
wonko-ga helps you.

Or visit http://en.wikipedia.org and look up "text mining", or other
terms which that article says are related to it.

Good luck.