Lab 1

NB The lab assignments will typically include write up instructions at the end. Before you start, read the whole assignment once, including the write-up instructions, so you know what to keep track of along the way.

Choose your language and stake your claim

Grammar Customization: Get a small grammar for English

LKB: Getting started

Try interactive unification

These instructions assume you are using the LUI interface, which I believe is on by default. If they don't make sense, try invoking (lui-initialize) at the LKB prompt.

Chain of identities

In the MRS assigned by this grammar to A cat chased me, the ARG0 value the _cat_n_rel is associated with the ARG1 value of the _chase_v_rel (that is, the cat is doing the chasing). In this part of the assignment, you will trace the chain of identities that connects these two.

Note that in addition to exploring the supertypes by searching through the .tdl files, you can also look at them through the LKB. For example, think of the constraint that you expect the lexical entry for "cat" to be contributing. Then:

Write up

Please submit write-ups as plain text files. (In future labs, that will help me run example sentences through your grammar. It also helps me reply to questions in your write up, by copying the questions into my grading rubric.)

Your write up should include:

  1. The four sentences you found that parse.
  2. The two (or more) strings you found that didn't parse.
  3. The names of the rules you used in interactive unification to see why they didn't parse.
  4. The tdl snippets that lead to the conflicting constraints for each non-parsing string, along with a prose description of what they do.
  5. A description of the chain of identities linking the ARG0 of _cat_n_rel to the ARG1 of _chase_v_rel in A cat chased me. Each link in the chain should say which instance is involved (e.g., lexical entry for cat), which supertype it inherits the constraint from, and show the tdl for the constraint. In addition, you should indicate which identity tag is enforcing the constraint. Your description should take the form of a numbered list.

    I find 13 links in this chain, counting the two constraints given in the example below as just one, since they come from the same type. To help you out, and to give you a sense of the format I'm expecting, here's one of them. (I picked this one because it is possibly the most obscure.)

    5. The head-spec phrase structure rule inherits the following
    constraints from basic-head-spec-phrase:
        HEAD-DTR [ SYNSEM [ LOCAL [ CONT.HOOK #hdhook ],
    	 [ LOCAL [ CAT [ VAL [ SPEC < [ LOCAL [ CONT.HOOK #hdhook ] > ] ],
                       CONT.HOOK #hook ] ],
        C-CONT [ HOOK #hook ] ].
    identifying the C-CONT.HOOK of the rule with the HOOK of the non-head
    daughter via #hook, and identifying the CONT.HOOK of the head daughter
    with the CONT.HOOK value inside the non-head daughter's SPEC via #hdhook.
  6. At least three questions that this lab caused you to wonder about. (Please indicate if you've figured out the answers, or if you would still like to see them addressed.)
  7. If you were unable to complete any part of the assignment, a description of the problems you encountered and what you think might be going on. (You can earn partial credit for any part of the assignment you couldn't get working by describing it in this section.)

Submit your assignment

Course materials borrow heavily from Linguistics 567: Knowledge Engineering for NLP at the University of Washington. Thanks to Emily Bender for letting us use them.