A research area that relates to the proposed permutation checking method is realisation ranking (Cahill and Forst, 2010;White and Rajkumar, 2012) where a system is given a set of text realisations and is asked to rate each text in the set.
in addition, if the difference between a permutation and its original sentence is only a single word movement, we add the POS tag of the moved word to the indicator function, so the feature becomes "EDiST_1-POS".