How are friend's Similarity determined?

Some people have very high similarity as me some low. I have no idea how the percentage is determined. Just curious.

I wonder too.  I think it is by bookshelf.

I think it goes by how you rate books.  Going by WL and bookshelf doesn't seem like a good way to do it. I frequently post books I hated, never read or were my daughter's or mother's books.  I also WL books for my daughter. 

It's always seemed pretty funky to me--Right now I have over 100% similarity to two of my PBS Friends--one shows as being 102% similar and one shows as being 120% similar.  Huh?  Does that mean they actually know more about what I want to read than I do myself?!!  LOL

Actually I think it has something to do with a new "cookie" TPTB have installed on the site.  It monitors key strokes, forum posts and frequency of visiting and then hooks you up with like-minded PBSers.

At least that's what I heard.

-RD

According to the Help Center: "The Similarity Index shows how "alike" you and your Friend are.  it is determined based on the information you provide to the club through your participation.  So when you apply star ratings to a book, add an item to your Wish List, or tell us what your favorite genres are, we're more able to come up with a profile of you as a reader.  And as others do the same, we can start matching up people who have similar tastes and habits."

James!!  You found it!  I have long wondered about this, and you have finally discovered the real explanation.

oh. That's a surpise. Me and the friend I have the highest percentage with don't have Any similar books on our WL.

Does anybody know if it's possible yet to search for people who are X% similar?

Robin