26 lines
727 B
Markdown
26 lines
727 B
Markdown
# Lexical semantics
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*The meaning of words*
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## NLP Tasks
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* Classifications tasks (e.g. spam detection)
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* Sequence tasks (e.g. text generation)
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* **Meaning** tasks. We study meaning in this section
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Useful for:
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* Information retrieval
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* Question answering
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* Topic modeling
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What do words mean?
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* Look in a **dictionary**
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## WordNet
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A lexical database:
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* Nodes are **synsets** (sets of synonyms)
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* Correspond to **abstract concepts**
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* **Polyhierarchical** structure, looks like a tree, but is flexible, nodes can have more than one parent.
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Using WordNet we can programmatically:
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* Identify **hyponyms** (child terms) and **hypernyms** (parent terms, we go up the tree for more general terms)
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* Measure **semantic similarity** |