Contents
How does Bert tokenizer work?
The BERT model receives a fixed length of sentence as input. Usually the maximum length of a sentence depends on the data we are working on. For sentences that are shorter than this maximum length, we will have to add paddings (empty tokens) to the sentences to make up the length.
How do you train a tokenizer?
Training the tokenizer
- Start with all the characters present in the training corpus as tokens.
- Identify the most common pair of tokens and merge it into one token.
- Repeat until the vocabulary (e.g., the number of tokens) has reached the size we want.
What is the context of a unigram tagger?
As the name implies, unigram tagger is a tagger that only uses a single word as its context for determining the POS (Part-of-Speech) tag. In simple words, Unigram Tagger is a context-based tagger whose context is a single word, i.e., Unigram.
How is unigram used in subword regularization?
Unigram is a subword tokenization algorithm introduced in Subword Regularization: Improving Neural Network Translation Models with Multiple Subword Candidates (Kudo, 2018). In contrast to BPE or WordPiece, Unigram initializes its base vocabulary to a large number of symbols and progressively trims down each symbol to obtain a smaller vocabulary.
How does a machine use a tokenizer system?
Machines don’t have this knowledge to leverage so they need to be told how to break text into standard units to process it. They do this using a system called “tokenization”, where sequences of text are broken into smaller parts, or “tokens”, and then fed as input into a DL NLP model like BERT.
Can a sentencepiece be built on any unigram model?
In principle, SentencePiece can be built on any unigram model. The only things we need to feed it are We then just train the SentencePiece tokenizer on the corpus, and we are free to perform the subword regularized (or not) NMT training. The beauty is we don’t even need to use subword regularization if we don’t want to.