Obviously, the superimposition of tags in the WEB method may change the tag of a tweet word such that it results in an unlikely tag sequence, as we will discuss later.
we also implemented type-constrained decoding (Täckström et al., 2013), i.e., prune the lattice such that the tweet words observed on the website have one of the tags they were labeled with on the website (soft constraints), or, alternatively, were forced during decoding to have the most frequent tags they were labeled with (hard constraint decoding), thereby focusing on licensed sequences.