Is there an algorithm that tells the semantic similarity of two phrases

Question

input: phrase 1, phrase 2

output: semantic similarity value (between 0 and 1), or the probability these two phrases are talking about the same thing

Answer 1

I would look into latent semantic indexing for this. I believe you can create something similar to a vector space search index but with semantically related terms being closer together i.e. having a smaller angle between them. If I learn more I will post here.