Meta-Neighborhoods

Traditional methods for training neural networks use training data just once, as it is discarded after training. Instead, in this work we also leverage the training data during testing to adjust the network and gain more expressivity. Our approach, named Meta-Neighborhoods, is developed under a multi-task learning framework and is a generalization of k-nearest neighbors methods. It can flexibly adapt network parameters w.r.t. different query data using their respective local neighborhood information. Local information is learned and stored in a dictionary of learnable neighbors rather than directly retrieved from the training set for greater flexibility and performance. The network parameters and the dictionary are optimized end-to-end via meta-learning. Extensive experiments demonstrate that Meta-Neighborhoods consistently improved classification and regression performance across various network architectures and datasets. We also observed superior improvements than other state-of-the-art meta-learning methods designed to improve supervised learning.