1. LING/C SC 581: Advanced Computational Linguistics
Lecture 25
April 16th

2. Previously
Introduced dbp (parsing and training) and evalb (evaluation).
You should have both programs working now.

3. Did anyone try parsing section 23?
course webpage file: wsj_23.txt.zip
try it!

4. Quick Homework 9
Let's use section 24 for testing:

5. Quick Homework 9
Part 1: use regexs to reformat saved wsj_24.txt into a wsj_24.lisp input suitable for the Bikel parser:
1346 sentences

6. Quick Homework 9 Note: Need to get rid of:
assume (for now) no gold POS information will be supplied to the parser.
Need to get rid of:
the file prefix
empty categories, e.g. *T* *U* *ICH* *EXP* * 0
indices, e.g. -1
etc. to turn the senttences into usable form:
(word1 word2 .. wordn)
Submit your Python (or Perl) regex conversion code

7. Quick Homework 9 Part 2: Parse it using supplied wsj-02-21.obj.gz
Evaluate the results with evalb:
give the Recall, Precision and F1 scores you obtained
Investigate what happens with:
-LRB- -LCB- and –RBR- -RCB- (left and right round/curly brackets)
Submit: by this weekend (ok?)