An LSTM is a Long Short Term Memory, a special veriant of Recurrent Neural Networks mainly used for Language modeling and sequence predictions. Bidirectional lstm is a network in which the data can make both both forwrd flow and backward flow at the same time. I this experiment we stacked up bidirectional lstms one above another in three layers to obtain the sentiment expressed in a text.
Test accuracy::
Conventional LSTM : 80.92%
Deep LSTM : 81.32%
Deep Bidirectional LSTM: 83.83%