Eckhard Bick - VISL

3.2 Morphological ambiguity in Portuguese
3.2.1 Overall morphological ambiguity
In order to quantitatively assess the ambiguity problem in Portuguese, before writing
disambiguation rules, I ran the morphological tagger on two larger chunks of corpus,
accessible to me at the time:
(a) a 630.000-word ECI-excerpt from the Borba-Ramsey corpus of written Brazilian
Portuguese
(b) a 132.000 word corpus derived from the on-line data base of Brazilian literature in
São Paulo (Rede Nacional de Pesquisa)
Table (1) shows the number and percentage of word form tokens with 0, 1, 2 ... 20
readings. The 1-readings row contains the figures for unambiguous cases, the 0readings
row covers recall failures.
(1) Table: morphological ambiguity in Portuguese
Number of
readings
Number of word form
tokens
- 115 -
%
cumulative %
mixed literature mixed literature mixed literature
0 2108 479 0.3 0.4 0.3 0.4
1 290131 62527 46.1 47.4 46.4 47.7
2 149148 30860 23.7 23.4 70.1 71.1
3 74142 15075 11.8 11.4 81.9 82.5
4 81732 17126 13.0 13.0 94.9 95.5
5 23837 4209 3.8 3.2 98.7 98.7
6 6582 1437 1.0 1.1 99.7 99.8
7 1043 159 0.2 0.1 99.9 99.9
8 520 79 0.1 0.1 100.0 100.0
9 9 1 - - - -
10 37 15 - - - -
11 16 2 - - - -
12 23 6 - - - -
13 4 0 - - - -
14 5 0 - - - -
15 6 3 - - - -
16 5 1 - - - -
17 1 1 - - - -
18 1 0 - - - -