ELMo
In plain wordsA 2018 model whose word representations changed with context, so 'bank' got different numbers in 'river bank' and 'bank loan'. It was a stepping stone between fixed word vectors and BERT.
A method (Embeddings from Language Models) that produced contextual word representations from a pretrained bidirectional language model: two stacked LSTMlong short-term memory, n.: A type of recurrent network with a separate memory lane and learned 'gates' that decide what to remember, forget and output, letting it keep track of information over long sequences. networks, one reading left to right and one right to left over character-based word inputs, trained to predict the next and the previous word on about a billion words of text. For a downstream task, the outputs of all the model's layers are mixed with weights learned for that task and supplied as additional input features to an otherwise unchanged task model. Because each vector depends on the whole sentence, ELMo separated senses that static word embeddingsword embedding, n.: A list of numbers standing for a word, learned so that words used in similar ways get similar lists. It lets a computer measure that 'cat' is closer to 'dog' than to 'car'. conflate, and adding it set new best results on six benchmarks covering sentiment, named entities, coreference, semantic roles, entailment and question answering. Fine-tuned transformers such as BERTBERT, prop. n.: An influential 2018 Google language model that learned to understand text by filling in hidden words. It made search engines and many language tools much better at grasping meaning in context. and GPTGPT, abbr.: Short for 'generative pre-trained transformer', the family of OpenAI models behind ChatGPT. The letters are also used loosely for any similar chatbot model. soon superseded it, but it showed that pretrained language-model representations transfer broadly.
Adding ELMo vectors to our tagger raised F1 by two points in 2018.
Origin
Introduced by Matthew E. Peters, Mark Neumann, Mohit Iyyer, Matt Gardner, Christopher Clark, Kenton Lee and Luke Zettlemoyer of the Allen Institute for AI and the University of Washington (arXiv, February 2018; NAACL 2018). Its Sesame Street name began a fashion continued by BERT and others.
Related
- word embeddingword embedding, n.: A list of numbers standing for a word, learned so that words used in similar ways get similar lists. It lets a computer measure that 'cat' is closer to 'dog' than to 'car'.
- BERTBERT, prop. n.: An influential 2018 Google language model that learned to understand text by filling in hidden words. It made search engines and many language tools much better at grasping meaning in context.
- long short-term memorylong short-term memory, n.: A type of recurrent network with a separate memory lane and learned 'gates' that decide what to remember, forget and output, letting it keep track of information over long sequences.
- transfer learningtransfer learning, n.: Reusing what a model learned on one task to get a head start on another — like a pianist picking up the organ faster than a beginner. It lets models learn new jobs from little data.
- language modellanguage model, n.: A system that has learned how likely different sequences of words are, so it can predict the next word in a text and, by doing that repeatedly, write text of its own.
- representation learningrepresentation learning, n.: Letting a computer work out for itself how best to describe its data, such as the edges and shapes in images or the meanings of words, instead of relying on descriptions people design by hand.
Sources
- Peters, M. E., Neumann, M., Iyyer, M., Gardner, M., Clark, C., Lee, K. & Zettlemoyer, L. (2018). Deep contextualized word representations. NAACL 2018. arxiv.org/abs/1802.05365
Mentioned in
Allen Institute for AIAllen Institute for AI, prop. n.: Paul Allen, a co-founder of Microsoft, created this nonprofit Seattle AI lab in 2014. It is known for releasing models together with everything used to build them, and for the Semantic Scholar paper search engine., word embeddingword embedding, n.: A list of numbers standing for a word, learned so that words used in similar ways get similar lists. It lets a computer measure that 'cat' is closer to 'dog' than to 'car'.