We tested values of α in {0, +∞} ∪ {10 q | q ∈ {0, 1, ..., 16}}.
recall that α = 0 ignores the morphology model probabilities altogether (using an unweighted lattice), 6 in a correspondence of a morphemes in one string with b in the other, the penalty is a + b − 2, since the morpheme on each side is not in violation.