TASK DEFINITION: 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.
PROBLEM: Sentence 1: A dog with a red toy in it's mouth. Sentence 2: A brown dog is carrying a stick in its mouth.

SOLUTION: 2

PROBLEM: Sentence 1: A person wearing a bike helmet talks on a cell phone. Sentence 2: A person wearing a helmet rides a bike near a white structure.

SOLUTION: 3

PROBLEM: Sentence 1: But the cancer society said its study had been misused. Sentence 2: The American Cancer Society and several scientists said the study was flawed in several ways.

SOLUTION:
2