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Formal evaluations of MT systems are particularly difficult to conduct, since there
is no agreed-upon "best output" for any single set of input data, and the multiple
"good outputs" are difficult to compare in a quantifiable way in order to achieve
a score. Since the first evaluation, there have been no new evaluations in
almost a decade (Chinchor 2000).
On the other hand, some level
of commercial use has been made of MT technology, as evidenced by the
BabelFish
translation system from Systran, available on AltaVista. However, the technology
has definite limitations, as anyone with some knowledge of foreign languages
will understand. For instance, if the user chooses to translate a page from French
into English, it will often be immediately obvious that the grammatical structure
of the original document has been retained in the translation.
Additionally,
idioms and proper names that do not exist in the "dictionary" used by the system
will either be translated literally, or simply left untranslated. Given this limitation,
if the user is familiar with the source language, one can often make sense of the
translation with the awareness that certain features of the original language
structure and form will affect the translation. "Word-sense disambiguation" is
an additional concern for MT systems, since many words can be translated in multiple ways.
Automatic word sense disambiguation can help a system determine which usage
of the word is meant - for example, the translation of the French word grille
could be made as either "railings, gate, bar, grid, scale, [or] schedule"
(Ide and Véronis 1998).
Elliott Macklovich, of the
Computational Linguistics Laboratory at the University of Montreal states that "for high-quality, polished
text, we just won't be able to dispense with [human translators] for some time"
(Caragata 1999). Later in the same article,
he clarifies: "All the machine has is access to the words, but you need more than
words to translate correctly. You need background knowledge, common sense and culture.
Machines have none of that."
When automatic systems were used
to translate languages for the Eurpean Union (which includes countries speaking
eleven different languages), the drafts produced had to be so heavily edited that
any savings in cost was eliminated (Caragata 1999).
The difficulty can be easily
illustrated. On a given day, I used the BabelFish translator to convert the following
two sentences from English into French, then from French back into English:
"Translating two languages automatically is a piece of cake".
"Summarization of text is no joyride".
The French translations are given below:
"La traduction de deux langages est automatiquement un morceau de gâteau".
"Summarization de texte n'est aucun joyride".
As you see, the English word "joyride" was not translated into French, since
the dictionary for the translation system did not apparently contain that word.
The English re-translations are given next, showing the stilted nature of the
new sentence structures:
"The translation of two languages is automatically a piece of cake".
"Summarization of text is not any joyride".
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