On Big Data Learning for Small Data Problems.
Much recent progress in machine learning have been fueled by the explosive growth in the amount and diversity of data available, and the computational resources needed to crunch through the data. This begs the question of whether machine learning systems necessarily need large amounts of data to solve a task well. An exciting recent development, under the banners of meta-learning, lifelong learning, learning to learn, multitask learning etc., has been the observation that often there is heterogeneity within the data sets at hand, and in fact a large data set can be viewed more productively as many smaller data sets, each pertaining to a different task. For example, in recommender systems each user can be said to be a different task with a small associated data set, and in AI one holy grail is how to develop systems that can learn to solve new tasks quickly from small amounts of data. In such settings, the problem is then how to "learn to learn quickly", by making use of similarities among tasks. One perspective for how this is achievable is that exposure to lots of previous tasks allows the system to learn a rich prior knowledge about the world in which tasks are sampled from, and it is with rich world knowledge that the system is able to solve new tasks quickly. This is a very active, vibrant and diverse area of research, with many different approaches proposed recently. In this talk I will describe a view of this problem from probabilistic and deep learning perspectives, and describe a number of efforts in this direction that I have recently been involved in.