Part 1: Reducing Feature Structure Complexity (Lars)

Whether to try to reduce the complexity of the feature structures that the Matrix and other grammars use (after Pollard and Sag).

(This section began as personal notes kept by Ned, so are somewhat biased towards where this area intersects with detecting linguistic phenomena. Sorry!)

Discussion

Emily: There is probably some scope for removing some features, difficulty will be convincing all the grammar developers.

Work required to explore this overlaps with Ned’s work…

Antske: Would be interesting comparing parts of the grammars that are shared, ie re-entrancies.

Emily: the points of the grammars where it’s interesting to compare them is in the MRS.

Start by comparing feature geometries across grammars. Similarities in the way grammars use structure sharing.

Start with Antske’s spring cleaning code to explore grammars. Yi’s student also has some Java code for doing stuff with TDL, more for the purposes of creating new representation that is more efficient.

Can also use Python code that the Matrix developers have for manipulating TDL.

Yi is interested in looking for detecting redundant features. Also doing things like looking for constraints that never lead to unification failure.

Next steps

First step: run tdl processing code through grammars and extract re-entrancies and value changes. This should be easy to do. Next: investigate which groupings are found, where feature-paths could be shortened. Finally, we would like to find the link between constraints used in the grammar and the linguistic ideas behind their location in the feature structure. This would however require careful analysis of the grammar.

Part 2: A Discussion on CLIMB (Antske)

Introduction from Antske:

How can we organize it to make grammar engineers more comfortable using it? Can we organize TDL in order to make it easier to read?

Have it so that you can define different parts of the types in different locations, such that it’s better organised by phenomena. But we want to make it so that you can still just write TDL without worrying about Python.

This sort of organisation would also allow for better comparison across grammars. It would allow us to build a cross-linguistic library of phenomena that would be a valuable resource.

Discussion

Ned: There’s the question of discoverability. How to make these libraries queryable?

Emily: Good to emphasize this in the development of grammars in this way. But we shouldn’t aim for perfect discoverability because phenomena will vary across grammars and languages; this just isn’t possible.

Antske: When testing for where phenomena are implemented it is common to parse a sentence and look at the types involved. It could be a good idea to have a place to document these discoveries.

Ned: It would be good to have a tool which helped faciliate this process of discovering the relevant types from grammar.

Emily: Doing a gDelta style clustering over types from attested examples of phenomena could be done here.

Emily: We need resources for this. Eg: we can’t come up with these examples for Wambaya like we can all do for English when probing the ERG.

Yi: Haven’t switched to CLIMB approach becuase we have a short period of time for a complete cycle in the development process (around 2 hours).

Having to switch between thinking about procedural code generation approach, and then the declarative approach of TDL adds an overhead. It would be nice for the whole thing to be done in the declarative level.

Emily: like the idea of having a declarative formalism which associates particular tdl with a flag saying which analysis it belongs to.

Antske: We need to look at what are clear and consise ways to define things like cross-classification etc.

Emily: There’ll always be two levels (the metagrammar and the grammar) but at least it would all be declarative.

Antske: Feedback from people starting to use these techniques would be great. Need to work out which things work, and which things could be done better.

Emily: making CLIMB declarative is a great idea.

Antske: Yes, and it’s also relativity feasible.

Emily: collecting more phenomena resources eg MRS test suite from NorSource

Emily: more discussion about this on Matrix list!

Ned: We need a centralised place on the wiki to start talking about phenomena based grammar engineering and resources. Volunteered to create a PhenomenaTop.

Next Steps

Antske will start to redefine CLIMB so that tdl can be used to write the metagrammar. The metagrammar should only require regroupments of types and constraints according to the phenomenon they implement or problem they solve (something that should be done for reasons of documentation anyway). Second, we need to start documenting phenomena at locations where they can be found easily. As a first start, we will use the delph-in wiki.

Last update: 2012-07-10 by EmilyBender [edit]