Ambiguities
It’s important to note that when we discuss ambiguities in the context of NLP, we don’t consider context at all. This is because, we focus on identifying and disambiguating the word’s potential meanings without relying on the broader sentence or discourse context, which might be considered in later stages of analysis like in Word Sense Disambiguation (WSD).
Lexical Ambiguity
Ambiguity caused by words in the sentence having 2 or more possible meanings.
There are two main types of lexical ambiguities, Homonymy and Polysemy.
Homonymy
A single spelling of a word (homographs) or groups of words that sound similar (homophones) but have unrelated meanings
Homophones (same pronunciation)
- ‘Pear’ vs ‘Pair’
- “buy/by two please!” (‘two’ is also a homophone lol)
Homographs (same spelling)
- ‘Lead’ - (to guide) vs (the metal)
- ‘’What a duck!” - (the action) vs (the animal)
Polysemy
Single words with multiple similar meanings
Note
- ‘Head’ - (body part) vs (social position)
- “I went right up to the bank” - (money place) vs (river bank)
Syntactic Ambiguity
‘Syntactic’ as in ‘Syntax’. When sentence structure is unspecific, meaning it has more than one possible structure, leading to multiple interpretations. This is typically caused by unclear or imprecise sentence construction.
Example: “John saw the boy with a telescope”
Breaking it down with Parse Tree
John using a telescope, saw the boy
Verb Phrase “Saw a boy” is linked to Prepositional Phrase “with a telescope” Implies, he did the action of seeing with the telescope
John saw the boy who had a telescope
Noun Phrase “a boy” is linked to Prepositional Phrase “with a telescope” Implies, boy has a telescope
Semantic Ambiguity
When a sentence has more than one meaning. This can be caused by Lexical or Syntactic Ambiguities. Some semantic ambiguities can persist even after resolving lexical and syntactic ambiguities, as some phrases or structures inherently have multiple interpretations.
For example:
“Nick met Nat in the lift lobby and then they went to his office.”
Although, this is a form of referential ambiguity… I can’t find an example of a purely semantically ambiguous phrase or sentence…
Summary
wrong diagram (to b fixed) todo
