Our basic feature representation is inspired from the feature representation of the MST parser (McDonald et al., 2005) except that in the parser the features represent a directed edge in the complete directed graph defined over the words in a sentence that is to be parsed, while our features are generated for word n-grams.
our feature set is a concatenation of two sets derived from the MST set described in Table 1 of (McDonald et al., 2005) in the following way: (1) In both sets the parent word in the parser's set is replaced with the represented word; (2) In one set every child word in the parser's set is replaced by the word to the left of the represented word and in the other set it is replaced by the word to its right.