Bidirectional LSTM

Chapter Goals:

• Learn about the bidirectional LSTM and why it's used

A. Forwards and backwards

The language model from the Language Model section of this course used a regular LSTM which read each input sequence in the forwards direction. This meant that the recurrent connections went in the left-right direction, i.e. from time step ttt to time step t+1t + 1t+1.

While regular LSTMs work well for most NLP tasks, they are not always the best option. Specifically, when we have access to a completed text sequence (e.g. text classification), it may be beneficial to look at the sequence in both the forwards ...