Our reordering model is defined as a simple linear model over the basic orientation types, similar to Cherry (2013).
our model defines score s φ (o, e, f ) over orientations o = {M, S, D}, and a sentence pair {e, f, a} with alignment a as a linear combination of weighted indicator features: where φ is a vector of weights, is a set of phrases that decompose the sentence pair {e, f, a}, and u(o, pp i , c i ) is a function that maps orientation o, phrase pair pp i and local context c i to a sparse vector of indicator features.