Meta Lifelong-Learning With Selective and Task-Aware Adaptation.

Meta-learning has been applied to lifelong language learning due to its ability to find an optimal model for efficient adaptation to any learned tasks. Generally, meta lifelong-learning partially stores samples from seen tasks in a memory and selects some of them to train the model, refresh the knowledge, and adapt the model for inference. However, the sample selection for these steps was usually done in a sub-optimal manner in existing work. Hence, we propose MeLSTA (Meta Lifelong-Learning with Selective and Task-Aware Adaptation) to effectively select the samples based on task identifiers and the adaptation scores reflecting the model behavior after adaptation. The results show that MeLSTA enhances the accuracy by 1.2% over the state-of-the-art while significantly shrinking the training duration by over 6 times. Additionally, our in-depth analysis reveals the strengths and limitations of MeLSTA and existing work, providing useful insights for future designs of meta lifelong-learning for NLP.