Note that the proposed extensions of Daumé III (2009) and Ando and Zhang (2005) only differ in how the domain-independent information is derived.
the extension of Ando and Zhang (2005) can be seen as a weaker version of the extension of Daumé III (2009) since the domain-independent information is used as is (i.e., x t ) in the former while first transformed by a domain specific LSTM in the latter (i.e., h t ).