Week 7 notes completed

CM3060 Natural Language Processing/Week 7/Week 7 Notes.md

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