Lab 3 (due 1/24 11:59 pm)

Overview

The goal of this lab is to take the grammar we got to last week and improve it for still more phenomena, again building out a small testsuite as you go. You'll also be using [incr tsdb()] to test the resulting grammar and compare it to your the grammar you built by the end of Lab 2.

This lab entails the following general steps:

1. Choose 3 additional phenomena to work on, not the same as last week (you can re-choose morphotactics, if you want to work on that some more):
   • negation
   • adnominal possession
   • coordination
     • Optionally with: agreement in NP coordination
   • pronouns (includes person/number/gender)
   • case
   • agreement
   • tense/aspect
   • Morphotactics
2. Document those phenomena in a testsuite
3. Process the extended testsuite with your lab 2 grammar.
4. Refine your choices file for the three phenomena you are working on.
5. Process the test corpus and your testsuite using [incr tsdb()], the LKB, and the grammar resulting from your updated choices file.
6. Examine the results of the second test run for coverage, accuracy and ambiguity, including as a diff to the final test run from last week.
7. Write it all up :)

Back to top

Create a small testsuite for three phenomena

Choose 3 phenomena to work on, from the following list:

• negation
• adnominal possession
• coordination
  • Optionally with: agreement in NP coordination
• pronouns (includes person/number/gender)
• case
• agreement
• tense/aspect
• Morphotactics

Create a small testsuite of examples, according to the general instructions for testsuites and the formatting instructions, illustrating the phenomena you worked on above. The testsuite should have both positive and negative examples, but doesn't need to be exhaustive (since we're working with test corpora this year), but you'll want both positive and negative examples for each of the phenomena you work on in this section. I expect these testsuites to have about 20-30 examples total by the end of this week, though you can do more if you find that useful. All examples should be simple enough that your grammar can parse them or fails to parse them because of the one thing that's wrong with them.

Create a test suite skeleton

1. Make a subdirectory called lab3 inside tsdb/skeletons for your test suite.
2. Edit tsdb/skeletons/Index.lisp to include a line for this directory, e.g.:

   (
   ((:path . "matrix") (:content . "matrix: A test suite created automatically from the test sentences given in the Grammar Matrix questionnaire."))
   ((:path . "corpus") (:content . "IGT provided by the linguist"))
   ((:path . "lab3") (:content . "Test suite collected for Lab 2."))
   )
   

3. Download the python script make_item, make sure it is executable, and run it on your test suite:

   make_item testsuite.txt

   Notes on make_item:

   • This script is going to be pretty picky about the format of your test suite. If you have questions, please post to Canvas (10 minute rule!).
   • It requires python3, which is on the current version of the Ubuntu+LKB appliance.
   • Alternatively, you can copy your testsuite and make_item over to patas and run there, or install python3 (from http://python.org/download) on your host OS (mac or windows), and run make_item outside VirtualBox.
   • If the above command is successful, testsuite.txt.item would be created in the working directory. If the testsuite contains errors, it's possible that a lot of output will appear on stderr. It maybe useful to redirect this into a file that you can use to go through and correct the errors one at a time. For example:

     ./make_item testsuite.txt item 2>errs

     The command just above attempts to create 'item' in the working directory, and stderr messages are redirected to the file 'errs'.

     make_item contains a default mapping from testsuite line types into particular fields of the [incr_tsdb()] item file. The default mapping puts 'orth' into 'i-input', the field which the is the input to the grammar. If your grammar targets a different testsuite line, override the default mapping with the -m/--map option.

     ./make_item --map orth-seg i-input testsuite.txt item

     The invocation above maps the orth-seg line into the input field.

     You can run make_item with -h/--help to see a summary of the options.

4. Copy the .item file which is output by make_item to tsdb/skeletons/lab3/item.
5. Copy tsdb/skeletons/Relations to tsdb/skeletons/lab3/relations (notice the change from R to r).

Back to top

Initial testsuite run

1. Create and run initial testsuite instances for both the linguist-provided data and your small testsuite, using the initial grammar.

   Note If your tsdb/ directory is inside a shared folder on VirtualBox, it will not work.

2. For each of these, explore the results, collect the following information to provide in your write up:
   • How many items parsed?
   • What is the average number of parses per parsed item?
   • How many parses did the most ambiguous item receive?
   • What sources of ambiguity can you identify?
   • For 10 items (if you have at least that many parsing), do any of the parses look reasonable in the semantics? (Emily can demo in class on Wednesday.)

Back to top

Improve the choices file for three phenomena

For the three phenomena you chose above, refine the choices file by hand. Please be sure to post lots of questions on Canvas as you work on this!

Make sure you can parse individual sentences

Once you have created your starter grammar (or each time you create one, as you should iterate through grammar creation and testing a few times as you refine your choices), try it out on a couple of sentences interactively to see if it works:

1. Load the grammar into the LKB.
2. Using the parse dialog box (or 'C-c p' in emacs to get the parse command inserted at your prompt), enter a sentence to parse. Alternatively, you can use Browse | Test items in [incr tsdb()] and just double click the item you want to parse. This sends the item to the LKB for interactive processing, but doesn't store the result in the test suite profile.
3. Examine the results. If it does parse, check out the semantics (pop-up menu on the little trees). If it doesn't look at the parse chart to see why not.
4. Problems with lexical rules and lexical entries often become apparent here, too: If the LKB can't find an analysis for one of your words, it will say so, and (obviously) fail to parse the sentence.

Note that the questionnaire has a section for test sentences. If you use this, then the parse dialog will be pre-filled with your test sentences.

Back to top

Run both the test corpus and the testsuite

Following the same procedure as the first time you ran your test corpus, do test runs over both the testsuite and the test corpus.

Again, collect the following information to provide in your write up:

1. How many items parsed?
2. What is the average number of parses per parsed item?
3. How many parses did the most ambiguous item receive?
4. What sources of ambiguity can you identify?
5. For 10 items (if you have at least that many parsing), do any of the parses look reasonable in the semantics? (Emily can demo in class on Wednesday.)

Back to top

Write up

Your write up should be a plain text file (not .doc, .rtf or .pdf) which includes the following:

1. Your answers to the questions about the initial and final [incr tsdb()] runs, for both test corpus and test suite, repeated here:
   1. How many items parsed?
   2. What is the average number of parses per parsed item?
   3. How many parses did the most ambiguous item receive?
   4. What sources of ambiguity can you identify?
   5. For 10 items (if you have at least that many parsing), do any of the parses look reasonable in the semantics? (Emily will demo in class on Tuesday.)
2. Documentation of the phenomena you have added to your testsuite, illustrated with examples from the testsuite.
3. Documentation of the choices you made in the customization system, illustrated with examples from your test suite.
   • This can be interleaved with the documentation of the phenomena (so you describe each phenomenon and then the choices you used to add an analysis of it to the grammar), but the documentation of the phenomenon and choices should be logically separate. Here's an example of what this should look like.
4. Descriptions of any properties of your language illustrated in your test suite but not covered by your starter grammar and/or the customization system.
5. If you have identified ways (other than those you reported last week) in which the automatically created choices file is particularly off-base, please report them here. If you can include IGT from the testsuite or your descriptive materials illustrating the problem, that is even better.

Back to top

Submit your assignment

• Be sure your write up (and the text-file version of your test suite, if you made a test suite this week, but this is not required) is included in your grammar directory.
• Likewise, make sure to include your most current tsdb profile in the grammar directory (ideally inside tsdb/home/).
• If you're using svn, export the grammar so I don't get all your .svn files:

  svn export yourgrammar iso-lab3
  
  For git, please do the equivalent.

• Create a tarball:

        tar czf iso-lab3.tgz iso-lab3
      

• Upload the tarball to Canvas.

Back to top

Back to course page