Identifying and Resolving Ambiguity

Steve Hoenisch

1 Examples of Ambiguity

Listed below are some headlines that exhibit at least one of three kinds of ambiguity -- lexical (part-of-speech), syntactic (structural), and semantic. In some of these examples -- all from actual newspaper headlines -- the unintended meaning is so strong that, on first reading, it overshadows the intended one.

drunk gets nine months in violin case

Iraqi head seeks arms

prostitutes appeal to pope

teacher strikes idle kids

squad helps dog bite victim

enraged cow injures farmer with ax

miners refuse to work after death

juvenile court to try shooting defendant

stolen painting found by tree

two Soviet ships collide, one dies

two sisters reunited after 18 years in checkout counter

2 Analysis of Ambiguity

2.1 Semantic Ambiguity


Iraqi head seeks arms

Ambiguity type: Semantic.

Identification and explanation: The homograph "head" can be interpreted as a noun meaning either chief or the anatomical head of a body. Likewise, the homograph "arms" can be interpreted as a plural noun meaning either weapons or body parts.

What makes headline humorous: The headline can easily be read as a disembodied head searching for arms (body parts) or wanting to have them attached.

Computational Resolution: The ambiguity could be resolved for a computer parser by specifying in the lexical entry for each item its semantic features.

2.2 Lexical Ambiguity


Teacher strikes idle kids

Ambiguity type: Lexical (part of speech or category ambiguity).

Identification and explanation: "strikes" can occur as either an verb meaning to hit or a noun meaning a refusal to work. Meantime, "idle" can occur as either an verb or an adjective.

What makes headline humorous: The headline can easily be read as "teacher hits idle kids' even though it was meant to mean that the walkout of teachers has left pupils idle.

2.3 Structural Ambiguity


Stolen painting found by tree

Ambiguity type: Structural.

Identification and explanation: The headline's two alternative syntactic representations make it structurally ambivalent:

(1) A tree found a stolen painting.

(2) A person found a stolen painting near a tree.

What makes headline humorous: The headline can easily be read as the representation in (1): A tree found a painting, which is humorous because trees, being inanimate, generally don't find things.

Computational Resolution: Specifying in the computational lexicon that the verb "find" usually takes an agent with the property [+animate].

3 Related

 Abstract: Abney's Memory Requirements and Lexical Ambiguities of Parsing Strategies

 Abstract: Marcus's Computational Account of Some Constraints on Language

 Abstract: Earley's Efficient Context-Free Parsing Algorithm

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