Thanks to the capability of knowledge transfer in ProgModel, M t can already remember quite much previously learned knowledge to give good label prediction in many cases.
we consider two types of decision engines: (1) t-IDE: ProgModel using only the output of M t as decision engine; (2) c-IDE: for i th word, it combines all outputs from is an indicator function which is 1 when i th word is in the vocabulary of M k and 0 otherwise.