Machine Translation: its History, Current Status, and Future Prospects

Elements ot the h i s t o r y , s t a t e of the a r t , and p robab l e f u t u r e of Machine T r a n s l a t i o n (MT) a r e d i s c u s s e d . The t r e a t m e n t i s l a r g e l y t u t o r i a l , based on the assumpt ion t h a t t h i s audience i s , f o r t he most p a r t , i g n o r a n t of m a t t e r s p e r t a i n i n g to t r a n s l a t i o n i n g e n e r a l , and MT in p a r t i c u l a r . The paper cove r s some of the major MT R&D groups , the g e n e r a l t e c h n i q u e s they employ(ed) , and the r o l e s they p l a y ( e d ) in t he development of the f i e l d . The c o n c l u s i o n s concern the seeming permanence of the t r a n s l a t i o n problem, and p o t e n t i a l r e i n t e g r a t i o n of MT w i t h mains t ream Computat ional L i n g u i s t i c s . I n t r o d u c t i o n Siemens Communications Systems, Inc . Linguistics Research Center U n i v e r s i t y of Texas Austin, Texas We are now into the fourth decade of MT, and there is a resurgence of interest throughout the world -plus a growing number of ~ and MAT (Machine-aided T r a n s l a t i o n ) sys tems in use by governments , b u s i n e s s and i n d u s t r y . I n d u s t r i a l f i rms a re a l s o beginning to fund M(A)T R&D projects of their own; thus it can no longer be said that only goverement funding keeps the field alive (indeed, in the U.S. there is no government funding, though the Japanese and European governments are heavily subsidizing MT R&D). In part this interest is due to more realistic expectations of what is possible in MT, and realization that MT can be very useful though imperfect; but it is also true that the capabilities of the newer MT systems lie well beyond what was possible just one decade ago. ~chine Translation (MT) of natural human languages is not a subject about which most scholars feel neutral. Thzs field has had a long, colorful career, and boasts no shortage of vociferous detractors and proponents alike. During its first decade in t he 1950"s, i n t e r e s t and suppor t was f u e l e d by v i s i o n s of h i g h s p e e d h i g h q u a l i t y t r a n s l a t i o n of a r b i t r a r y t e x t s ( e s p e c i a l l y t h o s e of interest t o the military and intelligence communities, who funded MT projects quite heavily). During i t s second decade in the 1960"s, disillusionment crept in as the number and difficulty of the linguistic problems became increasingly obvious, and as it was realized that the translation problem was not nearly so amenable to automated solution as had been thought. The climax came with the delivery of the National Academy of Sciences ALPAC report in 1966, condemning the field and, indirectly, its workers allke. The ALPAC report was criticized as narrow, biased, and short-sighted, but its recommendations were adopted (with the important exception of increased expenditures for long-term research in computational linguistics), and as a result MT projects were cancelled in the U.S. and elsewhere around the world. By 1973, the early part of the third decade of MT, only three government-funded projects were left in the U.S., and by late 1975 there were none. Paradoxically, MT systems were still being used by various government agencies here and abroad, because there was simply no alternative means of gathering information from foreign [Russian] sources so quickly; in addition, private companies were developing and selling MT sysEoms based on the mid-60"s technology so roundly castigated by ALPAC. Nevertheless the general disrepute of MT resulted in a remarkably quiet t h i r d decade . In light of these events, it is worth reconsidering the potential of, and prospects for, Machine Translation. After opening with an explanation of how [human] translation is done where it is taken seriously, we will present a brief introduction to MT technology and a short historical perspective before considering the present status and state of the art, and then moving on to a discussion of the future prospects. For reasons of space and perspicuity, we shall concentrate on MT efforts "in the U.S. and western Europe, though some other MT projects and less-sophisticated approaches will