Eckhard Bick - VISL

2412 words 1837 words 4249 words
Error types: errors % correct errors % correct errors % correct
Morphology (all) 29 98.8 % 7 99.6 % 36 99.2 %
unknown English
words in headlines
- 10
- 3
Morphology (pure) 16 99.3 % 6 99.7 % 22 99.5 %
Syntax (all) 66 97.3 % 46 97.5 % 112 97.4 %
syntax caused by
morphology
- 189 -
- 1
- 0
- 11
- 3
- 37 - 7 - 44
Syntax (pure) 29 98.8 % 39 97.9 % 68 98.4 %
3.9.3 Text type interference and tag set complexity
However, a closer look at the texts involved reveals that the news texts are quite
different from the prose fiction example, both lexically and syntactically. First of all,
there is a rather high percentage of complex names (e.g. 'Massachussets Institute of
Technology'), abbreviations ('MIT') and English loan words and vogue terms like 'joy
stick', 'bad boy' and the like. Thus a single word, console, which - used as an unknown
English noun ['video console'] and not as a Portuguese verb ['to comfort'] - is
responsible for a third (!) of all errors in the video game text. Second, VEJA news texts
are - syntactically - very rich in free predicatives (typically information about persons,
institutions or abbreviations, like age, place, definition etc.) all acting as false
"argument candidates" , as well as other types of parenthetical information, bracketing,
head lines and interfering "syntactically superfluous" finite verb forms in the form of
quotations, which all tend to blur the clause boundaries that otherwise would be
important structural information for the parser.
Still, none of the above problems are in principle intractable for the CGapproach,
and by providing for special features like these in the rule set (and lexicon)
error rates can be reduced for any text type.
One might assume that errors are evenly spread throughout the text, which
would - for an average sentence length of 15 words - mean about one morphological
error in every tenth sentence, and a syntactic error in every third. However, this is not
true: for all text types, errors appear in clusters, obviously most morphological errors
also appear in the list of syntactic errors, and many syntactic errors interfere with
readings in their neighbourhood, due to rules that depend on clause boundary words,
uniqueness principle and so forth. Thus, a V-N word class error not only affects
syntactic mapping and disambiguation for the word in question, but can cause 2 or 3