How to find similar phrases

Question

I have the following problem: I have created a customized Dictionary for getting used in some NLP tasks. I want to enhance my dictionary by finding phrases similar to the phrases I have in my dictionary. For example:

Lets say I have a phrase:
- take responsibility 
then, I should be able to find phrases like:
- hold accountable for 
-responsible for

I have just started learning NLP and I tried Word2Vec model over my dictionary but it only gives similar words that are already present in the dictionary. Is there any other algorithm that helps me find similar phrases using multiple sources.

Answer 1

One option is Word Mover’s Distance (WMD). WMD is an algorithm for finding the distance between phrases. WMD is based on word embeddings (e.g., word2vec) which encode 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

For your problem, you would have to generate candidates then use WMD to find the best matches for a given phrase.

Answer 2

Word2Vec model is used for vectorizing words. For vectorizing sentences ( phrases ) of varied length, we can use Google's Universal Sentence Encoder. Follow this blog and see the paper.

Basically, we will encode each phrase into a vector of say, 512, dimensions. This vector will have similarity with vectors of other similar phrases. We can use Cosine Similarity for determining the most similar phrases.