18. A computer readable storage medium storing computer readable instructions which, when executed by a processor associated with the computer, cause the computer to perform a computer-implemented method for identifying treelet translation pairs for use in a machine translation system that translates a source language input into a target language output, the computer-implemented method comprising: accessing a corpus of pairs of aligned, parallel syntactic dependency structures, each pair including a source language dependency structure having nodes that represent lexical items, the nodes being aligned with nodes representing lexical items in a target language dependency structure; enumerating connected sets of source nodes in the source language dependency structure as possible source treelets; identifying lexical items, and corresponding dependencies, in the target language dependency structure, that are aligned with the enumerated connected sets of nodes, as possible target treelets corresponding to the possible source treelets; extracting a plurality of well formed treelet translation pairs from the possible source treelets and the possible target treelets using the processor, wherein extracting comprises: limiting the step of extracting the well formed treelet translation pairs such that, for each given possible source treelet and its given corresponding possible target treelet, the given possible source treelet and given corresponding possible target treelet are only extracted as a well formed treelet translation pair if the lexical items in the given possible source treelet are only aligned with lexical items in the given corresponding possible target treelet and are not aligned with other lexical items in the possible target treelets that are different than the lexical items in the given corresponding possible target treelet, and the given possible source treelet and given corresponding possible target treelet are only extracted as a well formed treelet translation pair if the lexical items in the given corresponding possible target treelet are only aligned with lexical items in the given possible source treelet and are not aligned with other lexical items in the possible source treelets that are different than the lexical items in the given possible source treelet; and outputting the treelet translation pairs for use by a component in a machine translation system.
18. A computer readable storage medium storing computer readable instructions which, when executed by a processor associated with the computer, cause the computer to perform a computer-implemented method for identifying treelet translation pairs for use in a machine translation system that translates a source language input into a target language output, the computer-implemented method comprising: accessing a corpus of pairs of aligned, parallel syntactic dependency structures, each pair including a source language dependency structure having nodes that represent lexical items, the nodes being aligned with nodes representing lexical items in a target language dependency structure; enumerating connected sets of source nodes in the source language dependency structure as possible source treelets; identifying lexical items, and corresponding dependencies, in the target language dependency structure, that are aligned with the enumerated connected sets of nodes, as possible target treelets corresponding to the possible source treelets; extracting a plurality of well formed treelet translation pairs from the possible source treelets and the possible target treelets using the processor, wherein extracting comprises: limiting the step of extracting the well formed treelet translation pairs such that, for each given possible source treelet and its given corresponding possible target treelet, the given possible source treelet and given corresponding possible target treelet are only extracted as a well formed treelet translation pair if the lexical items in the given possible source treelet are only aligned with lexical items in the given corresponding possible target treelet and are not aligned with other lexical items in the possible target treelets that are different than the lexical items in the given corresponding possible target treelet, and the given possible source treelet and given corresponding possible target treelet are only extracted as a well formed treelet translation pair if the lexical items in the given corresponding possible target treelet are only aligned with lexical items in the given possible source treelet and are not aligned with other lexical items in the possible source treelets that are different than the lexical items in the given possible source treelet; and outputting the treelet translation pairs for use by a component in a machine translation system. 19. The computer readable storage medium of claim 18 wherein each child node of a parent node is considered to be connected to other child nodes of the parent node.