âGeneralization without Systematicity: On the Compositional Skills of Sequence-To-Sequence Recurrent Networksâ, 2017-10-31 (; backlinks; similar)â :
Humans can understand and produce new utterances effortlessly, thanks to their compositional skills. Once a person learns the meaning of a new verb âdaxâ, he or she can immediately understand the meaning of âdax twiceâ or âsing and dax.â
In this paper, we introduce the SCAN domain, consisting of a set of simple compositional navigation commands paired with the corresponding action sequences.
We then test the zero-shot generalization capabilities of a variety of recurrent neural networks (RNNs) trained on SCAN with sequence-to-sequence methods. We find that RNNs can make successful zero-shot generalizations when the differences between training and test commands are small, so that they can apply âmix-and-matchâ strategies to solve the task. However, when generalization requires systematic compositional skills (as in the âdaxâ example above), RNNs fail spectacularly.
We conclude with a proof-of-concept experiment in neural machine translation, suggesting that lack of systematicity might be partially responsible for neural networksâ notorious training data thirst.