Evaluate the similarity between them and classify them into classes from 0-5 as follows:
0 : The two sentences are completely dissimilar.
1 : The two sentences are not equivalent, but are on the same topic.
2 : The two sentences are not equivalent, but share some details.
3 : The two sentences are roughly equivalent, but some important information differs/missing.
4 : The two sentences are mostly equivalent, but some unimportant details differ.
5 : The two sentences are completely equivalent, as they mean the same thing.

Sentence 1: A young child rides a horse. Sentence 2: The little girl rode a horse.
3

Sentence 1: 3 Suspects Taken Into Custody in Boston Bombing Case Sentence 2: Boston police say 3 taken into custody in Marathon bombing
5

Sentence 1: You need to make up your mind. Sentence 2: You need to polish up on your logic skills.

1