Natural Language Processing · TEE · papers
Q6A · Pronoun approaches and lexical relations
Solved re-exam · February 2026
Actual re-examination · 9 February 2026 · 100 marks · 3 hours
ii. Describe the difference between Homonymy and Synonymy with suitable examples. Discuss how these two relations differently affect natural language processing applications? [10 marks]
Answer
i. Two approaches to pronoun resolution
| Approach | How it works | Advantage |
|---|---|---|
| Rule-based / syntactic | Uses parse structure, agreement, recency and linguistic constraints. Hobbs’ algorithm searches parse trees for eligible antecedents. | Interpretable: a proposed antecedent can be traced to explicit rules. |
| Statistical or neural | Learns candidate–pronoun compatibility or whole-document coreference patterns from labelled examples, using context and linguistic features or contextual embeddings. | Can learn interactions and contextual cues that are difficult to enumerate as hand-written rules. |
For “Asha dropped the glass because it was slippery,” a system should evaluate candidate referents and context rather than merely choose the most recent noun. Rules can constrain number and syntax; learned models can use compatibility patterns, though neither approach is guaranteed to resolve every ambiguity.
ii. Homonymy and synonymy
| Relation | Definition | Example |
|---|---|---|
| Homonymy | Same spelling or sound, unrelated meanings | bank as financial institution versus bank as river edge |
| Synonymy | Different words with the same or closely related meanings in a context | car and automobile; big and large |
Homonymy creates an ambiguity problem: a search for bank may retrieve finance or rivers. WSD uses context to choose the intended sense. Synonymy creates a vocabulary-matching problem: a document saying automobile may be relevant to a query saying car. Query expansion or semantic representations can improve recall by connecting related terms.
The remedies differ. Do not merge unrelated homonym senses simply because their spelling matches. Do not insist on exact surface-form matching when different words express the same concept. Synonyms are also context-sensitive: “big mistake” and “large mistake” are not always equally natural.
Yaad rakho: Homonym: same word-form, different meaning. Synonym: different words, similar meaning.