- Character-level tokens: In some cases, a token can be a single character, such as a letter or punctuation mark. This is often used in character-level language models or in applications like text classification.
- Variable-length tokens: Some models use variable-length tokens, which can be a combination of words, subwords, or characters. For example, a token might be a phrase like "hello world" or a sentence like "The quick brown fox jumps over the lazy dog".
The number of words that a token equates to can also vary. Here are some examples:
- Word-level tokens: 1 word per token
- Subword-level tokens: 1-5 words per token (depending on the subword size)
- Character-level tokens: 1 character per token
- Variable-length tokens: 1-10 words per token (depending on the token size)