Cross-lingual similar document retrieval methods

In this paper, we compare different methods for cross-lingual similar document retrieval. We focus on Russian-English language pair. We compare well-known methods like Cross Lingual Explicit Semantic Analysis (CL-ESA) with methods based on cross-lingual embeddings. We use approximate nearest neighbor (ANN) search to retrieve documents based entirely on distances between learned document embeddings. Also we employ a more traditional approach with usage of inverted index, with extra step of mapping top keywords from one language to other with the help of cross-lingual word embeddings. We use Russian-English aligned Wikipedia articles to evaluate all approaches. Conducted experiments show that an approach with inverted index achieves better performance in terms of recall and MAP than other methods.