A power mean based algorithm for combining multiple alignment tables

Most existing techniques for combining multiple alignment tables can combine only two alignment tables at a time, and are based on heuristics (Och and Ney, 2003), (Koehn et al., 2003). In this paper, we propose a novel mathematical formulation for combining an arbitrary number of alignment tables using their power mean. The method frames the combination task as an optimization problem, and finds the optimal alignment lying between the intersection and union of multiple alignment tables by optimizing the parameter p: the affinely extended real number defining the order of the power mean function. The combination approach produces better alignment tables in terms of both F-measure and BLEU scores.