Yhteystiedot

Yleisen kielitieteen laitos
PL 9 (Siltavuorenpenger 20 A)
00014 HELSINGIN YLIOPISTO

Puhelin +358 (09) 1911 (vaihde)
Faksi +358 (09) 191 29307

tulostettava versio

12. Probabilistic Parsing

• Lecture notes
  • NLTK 8.4: Probabilistic Parsing
• Further reading
  • Probabilistic Context-Free Grammars Markus Dickinson
  • Probabilistic Parsing Markus Dickinson
• Practical work
  • Copy the PCFG from Listing 8.5 (pcfg1.py).
    Make a grammar by nltk.parse_pcfg(string).
    Make a parser by nltk.ViterbiParser(grammar).
    Parse Jack saw telescopes.
  • Copy the PCFG from Listing 8.6 (viterbi_parse.py).
    Parse old men and women.
    Note: The Viterbi Parser returns only one parse.
  • To get multiple parses, use nltk.InsideChartParser(grammar)
    as shown in Listing 8.7 (bottom_up_chart_parsers.py).
    
  • Extend the grammar in order to parse:
    I saw the man with the telescope,
    I saw the old men and women with the telescope.