In this case, because the out-of-domain labeled data set (MRDA) is much larger, it overwhelms the model, inducing features that are not relevant for the task in the target domain.
when we provide the model with some labeled in-domain examples  Confusion matrices for (a) MLP conv-glove and (b) B-LSTM conv-glove on the test sets of QC3, TA, and BC3.