10. A non-transitory computer program product, encoded on a tangible program carrier, operable to cause a data processing apparatus to perform operations comprising: determining a plurality of error surfaces corresponding to a plurality of feature functions in a translation hypergraph, for each of one or more candidate translations represented in the translation hypergraph, including: generating a factor graph from the translation hypergraph, wherein the factor graph is an isomorphic transformation of the translation hypergraph, and generating the plurality of error surfaces from the factor graph; combining the plurality of error surfaces to produce a combined error surface; traversing the combined error surface to select weights for the feature functions that minimize error counts for traversing the combined error surface; and applying the selected weights to reduce an error count in a decoder that converts a sample of text from a first language to a second language.
10. A non-transitory computer program product, encoded on a tangible program carrier, operable to cause a data processing apparatus to perform operations comprising: determining a plurality of error surfaces corresponding to a plurality of feature functions in a translation hypergraph, for each of one or more candidate translations represented in the translation hypergraph, including: generating a factor graph from the translation hypergraph, wherein the factor graph is an isomorphic transformation of the translation hypergraph, and generating the plurality of error surfaces from the factor graph; combining the plurality of error surfaces to produce a combined error surface; traversing the combined error surface to select weights for the feature functions that minimize error counts for traversing the combined error surface; and applying the selected weights to reduce an error count in a decoder that converts a sample of text from a first language to a second language. 15. The computer program product of claim 10 , wherein the selected weights are applied to select a first candidate translation using Minimum-Bayes Risk (MBR).