The implementation of BiDAF is not exactly same as the one in the original paper

[Junjie Yang]

For the calculation of similarity matrix,

sim_matrix = tf.matmul(passage_encodes, question_encodes, transpose_b=True)

This is a simple dot product. But the original paper choose

where h is the passage representation and u is the question representation.
This maybe not a big problem, but it may still cause some difference.

[lkliukai]

Thanks for your comment! And we have to clarify that our implementation is not strictly same as the original one. And for the similarity matrix, we indeed select a simplified implementation. It may cause some differences, but we do not investigate significant performance difference for now.