ITS-2 : an interactive personal translation system 
Eric Wehrli and Mira Ramluckun 
Dept. of Linguistics- LATL 
University of Geneva 
1211 Geneva 4 
email: wehrli@uni2a.unige.ch 
ITS-2 is an interactive sentence translation system 
under development at the LATL lab of the Univer- 
sity of Geneva. In its current status, ITS-2 trans- 
lates French sentences into English or English into 
French over a still restricted vocabulary of approxi- 
mately 3'000 bilingual entries. The main objectives 
of this project are (i) to show some of the advantages 
of interactive approaches to NL translation, (ii) to 
demonstrate the merits of generative grammar as a 
syntactic model for MT, (iii) to show the feasibility 
of personal translation on small personal computers 
(under MS-Windows). 
ITS-2 is based on the familiar transfer architec- 
ture, with its three main components, parser, trans- 
fer and generation. The parser -- which is the IPS 
parser described in Wehrli (1992)-- associates with 
an input sentence a set of syntactic structures corre- 
sponding to GI3 S-structures, i.e. surface structures 
enriched with traces of moved elements and other 
empty categories. The role of the transfer component 
is to map source structures onto target structures. 
Transfer, which occurs at the D-structure level, is to 
a large extent a matter of lexical correspondence. 
For each lexical head of a SL structure, the lexi- 
cal transfer component consults the bilingual lexicon 
to retrieve the most appropriate TL item, which is 
then projected according to the X-bar specifications 
of the TL. Applied recursively over the whole SL D- 
structure, this process determines an equivalent TL 
D-structure. From these structures, the generation 
component derives well-formed S-structures, which 
are finally converted into the target sentence by mor- 
phological process. 
The current demonstration version of ITS-2 runs 
under MS-Windows. Integrated within a small edit- 
ing environment, it translates in real time a wide se- 
lection of sentences (French to English, or English to 
French) over a large range of grammatical construc- 
tions including simple and complex declaratives, in- 
terrogatives, relatives, passives, cliticization , some 
cases of coordination, efc. 
The system is interactive in the sense that it can 
request on-line information from the user. Typically, 
interaction takes the form of clarification dialogues 
or selection windows. Interaction can occur at sev- 
eral levels of the translation process. First, at the 
lexicographic level, if an input sentence contains un- 
known words or typos. In such cases, the user is 
asked to correct or modify the sentence. At the syn- 
tactic level, interaction occurs when the parser faces 
difficult cases of ambiguity, such as, for instance, 
when the resolution of an ambiguity depends on con- 
textual or extra-linguistic knowledge, as the case of 
some prepositional phrase attachments or coordinate 
structures. 
By far, the most frequent cases of interaction oc- 
cur during lexical transfer, due to the fact that lexical 
correspondences are generally of the many-to-many 
variety, even at the abstract level of lexemes. It is 
also at this level that our decision (not yet imple- 
mented) to try to restrict dialogues to the source 
language is the most challenging. While some cases 
of polysemy can be disambiguated relatively easily 
for instance on the basis of SL gender distinction, 
as in (1), other cases such as the (much simplified) 
ones in (2)-(3) are obviously much harder to han- 
dle, unless additional information is included in the 
bilingual dictionary. 
(1)a. Jean regarde les voiles. 
'Jean is looking at the sails/veils' 
(1)b. voiles: 
-maseulin (le voile) 
-fdminin (la voile) 
(2)a. Jean n'aime pas les avocats. 
'Jean doesn't like lawyers/avocadoes' 
(2)b. avocats: 
-homme de loi 
-fruit 
Another common case of interaction that occurs 
during transfer concerns the interpretation of pro- 
nouns, or rather the determination of their an- 
tecedent. In an sentence such as (3), the possessive 
son could refer either to Jean, to Marie or (less likely) 
to some other person, depending on contexts. 
(3) Jean dit ~ Marie que son livre se vend bien. 
'Jean told Marie that his/her book is selling well' 
In such a case, a dialogue box specifying all pos- 
sible (SL) antecedents is presented to the user, who 
can select the most appropriate one(s). 
In future work we intend to restrict the clarifi- 
cation dialogue to SL, to make ITS-2 available to 
monolingual users. 
REFERENCES . 
Wehrli, E. 1992. "The IPS system". COLING92. 
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