Transfer learning: the dos and don'ts

If you have recently started doing work in deep learning, especially image recognition, you might have seen the abundance of blog posts all over the internet, promising to teach you how to build a world-class image classifier in a dozen or fewer lines and just a few minutes on a modern GPU. What's shocking is not the promise but the fact that most of these tutorials end up delivering on it. To those trained in'conventional' machine learning techniques, the very idea that a model developed for one data set could simply be applied to a different one sounds absurd. The answer is, of course, transfer learning, one of the most fascinating features of deep neural networks. In this post, we'll first look at what transfer learning is, when it will work, when it might work, and why it won't work in some cases, finally concluding with some pointers at best practices for transfer learning.