Exercise: creating your own new grammar

For this exercise, you will create a small grammar from scratch using VisCCG. For your grammar, choose one of the following options:

1. work on grammar fragment for a language other than English.
2. or, a fragment for a particular domain that you are interested in.

If neither a language nor a particular domain jumps out at you, you can work with the sentences parsed and realized by the SHRDLU system. See the SHRDLU transcript for example sentences.

You should try to make sure that your grammar covers at least the following types of strings:

• Noun phrases, including adjectives: the big cat
• Intransitive sentences: Calvin sleeps
• Transitive sentences: Calvin saw Hobbes
• Ditransitive sentences: Calvin gave Hobbes the ball
• Sentential complement sentences: Susy thinks that Calvin saw Hobbes
• Object relative clauses: the ball that Calvin gave Hobbes
• Subject relative clauses: the boy that saw Hobbes

You should also handle at least one type of morphological behavior, e.g. books is book PL.

Your grammar should use expansions to reduce the amount of explicit specification that you must declare in the grammar. This can either be done to use inheritance or to deal with morphology.

You should have a testbed of at least 10 acceptable utterances and 5 unacceptable ones.

You should provide a write-up about your grammar that discusses the domain or language you chose, and the kinds of sentences and semantics that your grammar needs to cover. Point out any particularly interesting aspects of the domain or the language, like difficult ambiguities or highly agglutinative morphology. If you are working on a language other than English, please provide interlinearized glossed text when giving example sentences.

Discuss your grammar, briefly, noting anything that presented particular problems and whether you found any good solutions for them. Discuss how you used expansions.

Your submission should be added to the grammars in the OpenCCG wiki pages. Make sure to include your .ccg file as part of your hand-in, either in a link or as a <code> portion of your write-up, at the end. Comments in the file itself are very welcome. It should be possible for me to compile your file using ccg2xml and run your testbed of sentences on it.

To help with understanding OpenCCG and VisCCG, here are some resources to help you out.

• Obviously, the VisCCG tutorials.
• The GEAF paper on VisCCG: Baldridge, Chatterjee, Palmer, and Wing (2007).
• The OpenCCG Rough Guide provides help on creating grammars with the original XML formats, but may have some useful tips in general.
• For nice details on using hybrid logics to represent meaning, see White (2006)

Existing grammar writeups which should be useful for helping you complete this assignment:

• Tagalog (though the description of the implementation is incomplete at this point).
• Hup

If you are doing this exercise for a course, here is the rubric on which you’ll be scored:

Coverage:                       /20

Complexity of analysis:         /20

Complexity of implementation:   /20

Quality of write-up:            /20

Overall impression:             /20

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Total:                         /100