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Working with and developing a large grammar is a challenging process,
and the importance of having good visualization tools cannot be
over-emphasized. Currently the XTAG system has X-windows based tools
for viewing and updating the morphological and syntactic databases
([#!karp92!#,#!EgediMartin94!#]). These are available in both ASCII and
binary-encoded database format. The ASCII format is well-suited for
various UNIX utilities (awk, sed, grep) while the database format is
used for fast access during program execution. However even the ASCII
formatted representation is not well-suited for human readability. An
X-windows interface for the databases allows users to easily examine
them. Searching for specific information on certain fields of the
syntactic database is also available. Also, the interface allows a
user to insert, delete and update any information in the databases.
Figure 3.3(a) shows the interface for the morphology
database and Figure 3.3(b) shows the interface for the
syntactic database.
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(a) Morphology database |
(b) Syntactic database |
- [Interfaces database]{Interfaces to the database maintenance tools
XTAG also has a parsing and grammar development interface
([#!PSJ92!#]). This interface includes a tree editor, the ability to
vary parameters in the parser, work with multiple grammars and/or
parsers, and use metarules for more efficient tree editing and
construction ([#!becker94!#]). The interface is shown in
Figure 3.4. It has the following features:
- Menu-based facility for creating and modifying tree files and
loading grammar files.
- User controlled parser parameters, including the root
category (main S, embedded S, NP, etc.), and the use of the tagger
(on/off/retry on failure).
- Storage/retrieval facilities for elementary and parsed trees.
- The production of postscript files corresponding to elementary
and parsed trees.
- Graphical displays of tree and feature data structures,
including a scroll `web' for large tree structures.
- Mouse-based tree editor for creating and modifying trees and
feature structures.
- Hand combination of trees by adjunction or substitution for use
in diagnosing grammar problems.
- Metarule tool for automatic aid to the generation of trees by using
tree-based transformation rules
- [XTAG Interface]{Interface to the XTAG system
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Previous: Tree Grafting
XTAG Project
http://www.cis.upenn.edu/~xtag