Text Similarity Detection

Hi  I am  beginner to Rapid Miner. I want to use the Data to Similarity operator to check the text similarity but my problem is little different. I have a Excel file which has 2 columns (UserID & Review) and I want to check the text similarity of common userid.
For example - I have userid's A1, B1, C1, A1, B1, A1, B1, A1..etc now I want to check the text similarity of reviews given by A1  only.

UserID      Review
A1            I love McDonald
B1            McDonald is bad
C1            I love McDonald in Newyork
A1            I love McDonald
B1            abc love McDonald
A1            I love McDonald when I was in Paris.
B1            My Experience of McDonald is Pathetic
A1            I love it

I would appreciate if anyone can help me on it....

Thanks,
Arun