Section 13-1 to 13-3 Parsing I.md

Syntatic structure

This may be a method related to the parsing methods in compiling principles.The authors use the syntatic parsing to build a grammmar in the input of sentences.

13-1 Two views of linguistic structure

1.Constituency

headed phrase structure, we can use parsing trees to analyze the syntatic structure.

2.Dependency structure

The dependency structure shows which words depend on which other words.

13-2 Emprical Data Driven Approach to Parsing NLP

Pre 1990 ("Classical") NLP Parsing The rise of annotated data: The Penn Treebank, though not so useful in building a grammar, it's useful to: provide parsers and taggers, behave as a way to evaluate systems.

13-3 The Expotential Problem in Parsing-

1.Attachment ambiguities: key parsing decision how we attach various constituent 2.Two problems: 2.1 In parsing, there may be repeated work on parsing the similar parts when the sentence could have ambiguous meaning. 2.2 How do we work out the correct parse. e.g. Sydney Water breached an agreement with NSW Health.