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Table 4: Alternatives in Tagging the Verb reka
02 ANA rekana ‘V’ rek ‘Vroot’ an ‘Rec’ a
2.3 Quantitative Aspects of the Lexicon
rekane ‘V’ rek ‘Vroot’ an ‘Rec’ e ‘Per’
rekanwa ‘V’ rek ‘Vroot’ an ‘Rec’ w ‘Pas’ a
rekanwe ‘V’ rek ‘Vroot’ an ‘Rec’ w ‘Pas’ e ‘Per’
There are a few marked tendencies in the quantitative distribution of lexical items
in Northern Sotho, especially with respect to the relationship between frequency of
use and ambiguity.
In our 43,000 word corpus sample, we counted types and tokens, distinguishing
nouns, verbs and closed class items. In Northern Sotho, only nouns and verbs allow
for productive word formation (i.e., are open word classes), whereas function words,
adverbs and adjectives are listed (i.e., belong to closed classes). Note that we did
not consider numerals at all; the figures given are to be taken as tendencies. We
separately counted forms that can be unambiguously identified as nouns, verbs or
elements of one of the closed classes, as opposed to ambiguous forms where more
than one word class can be assigned, depending on the context.
All three have many more unambiguous types than ambiguous ones. As is likely in
most languages, however, high frequency items are also highly ambiguous (cf. Table 5
below). Nevertheless, if only slightly more than half of the potential verb occurrences
in the sample are unambiguous (ca. 5000 tokens), the percentage of unambiguous
occurrences of noun candidates is as high as 90% (5800 out of 6300 tokens). Ambiguity
with nouns is restricted to rather infrequent items. For closed class items, however,
the inverse situation is observed: only little more than 20% of the occurrences of
closed class items in our sample are unambiguous, and a small set of closed class item
types (88 types), of an average frequency of two hundred or more, constitutes about
40% of the total amount of word forms in the sample. We expect that this distribution
will be more or less generalisable to larger data sets of Northern Sotho. It will have
an incidence on our approach to the bootstrapping of linguistic resources for this
language. Table 5 lists the most frequent (and at the same time most ambiguous)
items from the 43,000 word corpus sample with their tags (according to the tagset
described in section 3.2) and their absolute frequency in the sample.
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