Networks for sequence data
In addition to image data, natural language text has also been a frequent topic of interest in neural network research. However, unlike the datasets we've examined thus far, language has a distinct order that is important to its meaning. Thus, to accurately capture the patterns in language or time-dependent data, it is necessary to utilize networks designed for this purpose.
RNNs and LSTMs
Let's imagine we are trying to predict the next word in a sentence, given the words up until this point. A neural network that attempted to predict the next word would need to take into account not only the current word but a variable number of prior inputs. If we instead used only a simple feedforward MLP, the network would essentially process the entire sentence or each word as a vector. This introduces the problem of either having to pad variable-length inputs to a common length and not preserving any notion of correlation (that is, which words...
