15. A computer-readable non-transitory storage medium comprising executable instructions that, when executed by a computing device, cause the computing device to: generate a set of vectors of parameters of a translation system that uses syntactic and semantic descriptions; translate, by the translation system using the vectors of parameters, a natural language text to produce a first plurality of translated texts; determine a first vector of translation quality ratings reflecting translation quality of the first plurality of translated texts; modify at least one parameter of each vector of parameters to produce a plurality of vectors of modified parameters; translate, by the translation system using the vectors of modified parameters, the natural language text to produce a second plurality of translated texts; determine a second vector of translation quality ratings reflecting translation quality of the second plurality of translated texts; and responsive to determining that an element of the second vector of translation quality ratings exceeds a corresponding element of the first vector of translation quality ratings, modify a vector of parameters based on a corresponding vector of modified parameters.
15. A computer-readable non-transitory storage medium comprising executable instructions that, when executed by a computing device, cause the computing device to: generate a set of vectors of parameters of a translation system that uses syntactic and semantic descriptions; translate, by the translation system using the vectors of parameters, a natural language text to produce a first plurality of translated texts; determine a first vector of translation quality ratings reflecting translation quality of the first plurality of translated texts; modify at least one parameter of each vector of parameters to produce a plurality of vectors of modified parameters; translate, by the translation system using the vectors of modified parameters, the natural language text to produce a second plurality of translated texts; determine a second vector of translation quality ratings reflecting translation quality of the second plurality of translated texts; and responsive to determining that an element of the second vector of translation quality ratings exceeds a corresponding element of the first vector of translation quality ratings, modify a vector of parameters based on a corresponding vector of modified parameters. 18. The computer-readable non-transitory storage medium of claim 15 , further comprising executable instructions causing the processing device to: repeat the translating operation using the vector of parameters responsive to evaluating a terminating condition.