minutes from the XTAG meeting on 22nd July 1999

This is the meeting summary from the meeting on 22nd july where Anoop and
Shuly talked about the feature errors discovered by type-checking the XTAG
feature structures. 


Errors found in XTAG feature structures after type-checking against a

There were four main types of errors found:

1. Grammar-based: ambiguous names, or ambiguous functions for
2. Typos.
3. Undocumented.
4. Incorrect or obsolete feature.

The errors discussed during the meeting were the following. There are
a few others in the list, but they are of the same types as the ones

1. <assign-comp> has some non-overlap in feature values compared to <comp>
   <assign-comp> extras = { ecm, ppart_nil, none }
   <comp> extras = { nil }

   - type of error: possibly ambiguous, grammar-based
   - fix: possible duplication of effort for <assign-comp>
   - cannot fix without detailed knowledge of <assign-comp>

2. <case> = nom ==> nominative
   <mode> = nom ==> nominal/adjectival predicate

   - type of error: typo
   - fix: change <mode> = nom to <mode> = pred

3. <rel-pron> has overlap with <mode> but has extra values
   <rel-pron> extra values = { ppart, ger, adj_clause }

   - type of error: possibly ambiguous, grammar-based
   - fix: dunno

4. <relpron> exists alongside <rel-pron>

   - type of error: typo
   - change <relpron> to <rel-pron>

5. <disc-conj> not documented

   - type of error: documentation
   - fix: add to tech-report
   - prolly stands for discourse conjunction

6. <predet> occurs in noun and det signs

   - type of error: incorrect feature
   - fix: should be removed since Carlos thinks it was widely removed
   - from the grammar at some point and remainder were skipped

7. <gen> occurs ambiguously, stands for 'gender' as well as 'genitive'
   - type of error: ambiguous, grammar-based
   - fix: should change all occurences of <gen> in noun signs to
   - another name, say <gendr>

8. In one tree, NP.b:<assign-case> = N.t:<case>

   - type of error: typo
   - fix: change <assign-case> to <case>

9. <punct> is defined as a complex feature, e.g. <punct contains
   comma> but instances of <punct> are found in the grammar.

   D_r.b:<punct bal> = Punct_1.t:<punct>

   - type of error: incorrect feature
   - fix: dunno

10. In tree PsPu:

   S_f.t:<assign-comp> = ind/...

   - type of error: unknown
   - check lexical features to see if 'ind' is allowed for
   - <assign-comp>

11. Should we have case on sentential subjects?

   - type of error: grammar-based
   - fix: remove all instance of <case> = nom or <assign-case> = nom
   - in sentential subject tree families.