number of tokens in the source
number of tokens in the target
ratio of source and target sentences lenght
target word
left context of the target word
right context of the target word
source word aligned to the target word
left context of the aligned source word
right context of the aligned source word
target word is stopword
target word is punctuation mark
target word is proper noun
target word is digit
highest order of ngram that includes target word and its left context
highest order of ngram that includes target word and its right context
backoff behavior of ngram w_{i-2} w_{i-1} w_{i} (w_{i} - target word)
backoff behavior of ngram w_{i-1} w_{i} w_{i+1}
backoff behavior of ngram w_{i} w_{i+1} w_{i+2}
highest order of ngram that includes source word and its left context
highest order of ngram that includes source word and its right context
POS of the target word
POS of the aligned source word
target word + left context
target word + right context
target word + aligned source word
POS of target word + POS of aligned source word
target word + left context + source word
target word + right context + source word