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Kimmo Koskenniemi

Kimmo Matti Koskenniemi
Born September 7, 1945, Jyväskylä

Master of Science 1967 (mathematics), Licentiate (general linguistics and computer science), PhD 1984 (general linguistics), University of Helsinki

Professor of computational linguistics/ language technology 1991–2012, University of Helsinki
Senior research fellow 1985–90, Academy of Finland, University of Helsinki
Senior programmer 1981–84, Academy of Finland, University of Helsinki
Mathematician, section manager and research associate 1967–80, University of Helsinki Computing Centre.

Research themes:
Automatic morphological analysis, i.e. the recognition of word forms and the application of the methods to historical linguistics as well as to dialects and to language forms which are old or which otherwise display variation.


Written by Kimmo Koskenniemi (Olli Siitonen ed.)
Translated by Matthew Billington

Thesis and the two-level morphological model

After having studied both computer science and general linguistics, I sought for solutions by combining knowledge from both fields. As a researcher, I became involved in an Academy of Finland project (1981–84), led by Fred Karlsson, which was investigating automatic recognition of the Finnish language.

Already in the first month Lauri Karttunen, then a professor in Austin, Texas, came to visit. When he heard what I had thought was roughly the target of my work, he invited me to a seminar in Austin later that spring, which was to be attended, in particular, by Ron Kaplan and Martin Kay, who had been working with similar kinds of ideas. I got funding and off I went.

Professor Fred Karlsson and Kimmo Koskenniemi, then section manager, teaching Finnish to a computer at the Department of General Linguistics. Photo: 1983, Helsinki University Museum/ Liisa Karvonen.

I gained a first-hand picture of their work and insights. The method was well suited to English, but problems arose due to the high incidence of phoneme alternations in Finnish. I worked away at both their ideas and my own until December, when the pieces of the puzzle began to fall into place. Instead of Kaplan and Kay’s cascade model, I succeeded in getting a method to work with parallel rules. Formulating them was just as easy as with traditional rules, but the computer was also able to implement extensive systems of rules in a light way. Thus, the so-called two-level model for morphological analysis was born, and in the following three months I completed the theory along with a preliminary description of the morphology of Finnish words and a computer program that recognised words in practice. The program was language independent, and soon linguists were producing their own two-level descriptions in over a dozen different languages. I concentrated on using the method as the basis for my doctoral dissertation, which took 18 months.

The defence of Professor Koskenniemi’s thesis. In the photograph are his opponent, Lauri Karttunen (left.), and his thesis supervisor, Fred Karlsson. Photo: Professor Koskenniemi’s home archive.


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