Sigrún Helgadóttir

A Mixed Method Lemmatization Algorithm Using a Hierarchy of Linguistic Identities (HOLI)

We present a new mixed method lemmatizer for Icelandic, Lemmald, which achieves good performance by relying on IceTagger [1] for tagging and The Icelandic Frequency Dictionary [2] corpus for training. We combine the advantages of data-driven machine learning with linguistic insights to maximize performance. To achieve this, we make use of a novel approach: Hierarchy of Linguistic Identities (HOLI), which involves organizing features and feature structures for the machine learning based on linguistic knowledge. Accuracy of the lemmatization is further improved using an add-on which connects to the Database of Modern Icelandic Inflections [3]. Given correct tagging, our system lemmatizes Icelandic text with an accuracy of 99.55%. We believe our method can be fruitfully adapted to other morphologically rich languages.

Morphosyntactic Tagging of Old Icelandic Texts and Its Use in Studying Syntactic Variation and Change

We describe experiments with morphosyntactic tagging of Old Icelandic (Old Norse) narrative texts using different tagging models for the TnT tagger [3] and a tagset of almost 700 tags, originally developed for Modern Icelandic. It is shown that by using a model that has been trained on both Old and Modern Icelandic texts, we can get 92.7% tagging accuracy which is considerably better than the 90.4% that have been reported for Modern Icelandic. Although our tagging is morphological in nature, the tags carry a substantial amount of syntactic information and the tagging is detailed enough for the syntactic function of words to be more or less deduced from their morphology and the adjacent words. We show that the morphosyntactic tags can be very useful in locating certain syntactic constructions and features in a large corpus of Old Icelandic narrative texts. We demonstrate this by searching for—and finding—previously undiscovered examples of a number of syntactic constructions in the corpus.We conclude that in a highly inflectional language, a morphologically tagged corpus can be an important tool in studying syntactic variation and change, in the absence of a fully parsed corpus which of course gives more possibilities.

Edentulousness in Iceland in 1990: A national questionnaire survey

Levels of edentulousness were established for seven age groups by means of self-administered questionnaires. The percentage of edentulousness in the Icelandic adult population (18 years and over) was 20.7%. Edentulousness was first reported in the 35- to 44-year-olds and increased rapidly with age. Women had a higher level of edentulousness than men, and the percentage of edentulous people in Reykjavík was significantly lower than in towns, villages, and rural areas. The proportion of edentulous 35- to 44-year-olds and those 65 years old or older was significantly lower than in a similar study in 1985. The percentage of 18- to 79-year-old edentulous Icelanders in 1990 decreased considerably from the results of a national survey on oral health performed in 1962, mainly as a result of a major reduction of edentulousness in the younger age groups and among women.