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 bird holding on to a metal gate. Sentence 2: A multi-colored bird clings to a wire fence.

SOLUTION: 3

PROBLEM: Sentence 1: Thousands evacuated in Moscow metro fire Sentence 2: Thousands evacuated after fire breaks out in Moscow Metro

SOLUTION: 5

PROBLEM: Sentence 1: international atomic energy association is the united nations watchdog. Sentence 2: the international atomic energy agency is the u.n.'s nuclear watchdog.

SOLUTION:
5