Eckhard Bick - VISL

VFIN 9185 3748 19 375 1079 540 28274
INF 11 0 0 0 26 4664
GER 0 0 0 1 35
PCP 88 16 23 5033
ADV 2670 33 7023
PROP 283 3762
all 54633
words: 69603 17950 30619 4970 903 5335 13938 11704 121170
Since this statistical analysis ignores closed class, the overall ambiguity figures will
obviously be lower than what is found for the language as a whole (about 1.7 readings
pr. word form when using portmanteau tags, 2.0 when not). When also ignoring word
class internal inflexion and subclass ambiguity (shaded), the 121.170 potential open
class words get 155.022 different word class readings (about 1,28 pr. potential open
class word form). In all, the text contains 170.998 open class readings (about 1,41 pr.
potential open class word form). The remaining 0,3 readings pr. word form (to reach
1,7) can be accounted for as the sum of cross-group ambiguity between the closed and
open word class groups, plus closed-class internal ambiguity.
As can be seen, the most common ambiguity is the N-VFIN class, followed
closely by N-ADJ and VFIN-VFIN internal ambiguity. Of these, the first is syntactically
most important, since an error here will cause additional errors in the syntactic tags. The
risk of such error spreading is smaller for N-ADJ and very small for word class internal
ambiguities like VFIN-VFIN.
Apart from sheer number, the importance of an ambiguity class must, however, be
measured against the size of the word classes in question. Thus, N is a very large word
class, so maybe this explains its ambiguity rating in absolute terms, - but how large is
the ambiguity risk for, say, a noun in relative terms?
(2) Table: relative frequencies for word class ambiguity
WC2 N ADJ VFIN INF GER PCP ADV PROP ambiguity
WC1 (%) (%) (%) (%) (%) (%) (%) (%) index
N 3.1 13.3 15.7 1.1 0.0 3.1 3.0 2.8 42.2
ADJ 51.6 1.3 13.2 0.6 0.0 13.0 6.5 5.1 91.5
VFIN 35.8 7.7 30.0 12.2 0.1 1.2 3.5 1.8 96.0
INF 15.4 2.3 75.4 0.2 0.0 0.0 0.0 0.5 93.8
GER 0.7 1.0 2.1 0.0 0.0 0.0 0.0 0.1 3.9
PCP 41.2 43.7 7.0 0.0 0.0 1.6 0.3 0.4 94.3
ADV 14.8 8.3 7.7 0.0 0.0 0.1 19.2 0.2 50.4
PROP 16.6 7.8 4.6 0.2 0.0 0.2 0.3 2.4 32.2
all 45.1
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