lmthang
commented
6 years ago Hi jongsae,
I think gnmt_v2 is a main factor then SGD. normed_bahdanau is better than bahdanau attention; scaled_luong is good, but somehow I couldn't get it to work with gnmt_v2. For optimizer, what I observed personally is Adam makes things easier to train but if you can manage to train with SGD with large learning rate, you will get better result! In fact, in all my NMT papers in 2014-2016, I used a pretty universal set of hyperparameters: sgd, learning rate 1.0, uniform init 0.1, grad norm 5, dropout 0.2 :)
Hope that helps!
ghost
frajos100
Hi, I am trying to reproduce the training results I generated using google/seq2seq on tensorflow/nmt.
I noticed that standard hyperparams provided here lead to much higher BLEU score (15.9 vs. 21.45 BLEU) when the same number of steps (80K) are trained. Is it because of the algorithmic changes such as normed_bahdanau and gnmt_v2, or is it because of the optimized implementation of NMT? Or because of any reasons else?
One more thing is, it uses SGD instead of Adam, which was the default of google/seq2seq. Moreover, the used learning rate is surprisingly high (1.0). Maybe the optimizer changes affected the training curve? I think Adam is more commonly used these days, so why is SGD selected in this case?
I would appreciate any explanations or comments that help me understand the algorithmic and implementational differences between these two trainings.