Choosing the right corpus to build a TF IDF Vectorizer used for comparing the similarity of two strings
Word Mover’s Distance (WMD) is an algorithm for finding the distance between pairs of strings. It is based on word embeddings (e.g., word2vec) which encoded the semantic meaning of words into dense vectors.


  The WMD distance measures the dissimilarity between two text documents as the minimum amount of distance that the embedded words of one document need to "travel" to reach the embedded words of another document.


For example:


Source: "From Word Embeddings To Document Distances" Paper