Neural machine Translation
Statistical Machine Translation
Even with large training corpora, unknown words in the test data will appear.
Unknown Words is the main subject of 13 publications. 2 are discussed here.
Topics in LinguisticProblemsUnknown Words | Morphology | Generating Rich Morphology | Factored Translation Models | Compounds | Translating Tense Case Markers | Translating Chunks And Clauses | Document Level Aspects | Transliteration | Syntactic Prereordering | POS Chunk Prereordering | Syntactic Reranking | Integrating Syntactic Features