What shortcomings do you see with deep learning? originally appeared on Quora - the knowledge sharing network where compelling questions are answered by people with unique insights.
Answer by Oren Etzioni, CEO of the Allen AI, Founder of Farecast, Professor at UW, CSE, on Quora.
Deep Learning has been incredibly successful in recent years, but it is still merely a tool for classifying items into categories (or for nonlinear regression).
We have seen outstanding results in mapping images, audio segments, even board positions, into categories with ever-increasing accuracy, but AI needs to go way beyond classification and regression.
Let's talk about AlphaGo, which is a phenomenal technical achievement by the team at DeepMind.
Yet, the overblown claims about the impressive success of AlphaGo are a case of a person climbing to the top of the tree and shouting "I'm on my way to the moon!"
Here's why:
- AlphaGo relied on a massive amount of labeled data, which is easily available in games, and often unavailable in other contexts. Consider, for example, classifying citations into "influential" versus "not" in Semantic Scholar---while unlabeled data is plentiful---labeled data is difficult-to-obtain.
- We don't know how to build sophisticated background knowledge or reasoning capabilities into deep learning systems.
- AlphaGo relied on a set of manually-crafted neural networks, that have to be changed from application to application.
- AlphaGo relied on people to specify its input representation and its output target categories--it cannot specify its own.
- In many cases, even specifying the appropriate categories is difficult due to nuance, ambiguity, etc.
The bottom line is: when we successfully define an objective function and reduce a real-world task to an optimization problem---our CS "muscles" kick into overdrive, and we can solve it given enough data and a successful representation (sooner or later). However, may problems are ill-structured and require additional analysis to even formalize. For example, how do we formally write down the meaning of a single sentence?
Most of these comments are not specific to AlphaGo or Deep Learning, but are broadly applicable to all supervised learning programs. As Alan Newell said (in a different context), "you can't play 20 questions with nature and win!"
With all due respect to the brilliant Geoff Hinton---thought is not a vector, and AI is not a problem in statistics.