tailieunhanh - Báo cáo khoa học: "A TWO-WAY APPROACH TO STRUCTURAL TRANSFER IN MT"

The METAL machine translation project incorporates two methods of structural transfer - direct transfer and transfer by grammar. In this paper I discuss the strengths and weaknesses of these two approaches in general and with respect to the METAL project, and argue that, for many applications, a combination of the two is preferable to either alone. | A TWO-WAY APPROACH TO STRUCTURAL TRANSFER IN MT Rebecca Root Linguistics Research Center University of Texas . Box 7247 Austin Texas 78712 USA Abstract The METAL machine translation project incorporates two methods of structural transfer - direct transfer and transfer by grammar. In this paper I discuss the strengths and weaknesses of these two approaches in general and with respect to the METAL project and argue that for many applications a combination of the two is preferable to either alone. 1. Introduction One of the central design questions in machine translation is that of the best method of structural transfer that is the conversion from the syntactic analysis structure of the source language to the syntactic generation structure of the target language. Although several of the various approaches to this -interlingua transfer grammar and direct transfer Slocum 84 share a number of properties which render a choice among them of relatively little consequence there is at least one point of variance that can have significant practical ramifications. This is the choice between the use of an independent grammar as one finds in the interlingua and transfer grammar approaches and direct transfer where transfer specifications are tied directly to source language structures. Since each method has its advantages and disadvantages there is no basis for favoring one over the other independent of a particular application. However it is highly likely that for a system with any significant range of application neither approach will be completely satisfactory. Furthermore decisions made in the design of other components of the system may render a homogeneous approach to transfer impractical. For both of these reasons we have implemented in METAL a scheme for transfer which is sufficiently flexible to allow for the use of both direct transfer and transfer by grammar. This is done in such a way as to put control of the interaction in the hands of the grammar writer allowing