These systems do perform better because they’re more focused on a specific domain. It’s the same way people work. We don’t tend to ask a journalist for cancer advice, and we don’t generally ask an oncologist for real estate advice. People tend to specialize in things and know them well. It’s the same thing with AI. Mathematically, you’re just more likely to get the answer if you’re clear about the domain to begin with.
FORTUNE: Let’s focus on Watson for Oncology, for a moment. One of the challenges of a disease like cancer is that its progression, particularly in later stages of metastasis, can often look like an emergent system. The disease often doesn’t follow a linear progression—even in the same tumors, certain cell populations can have radically different genetic mutations, meaning that they can respond differently to treatment. How does Watson learn to master chaos?
KENNY: Let me offer an example of that. It’s the work I did in weather—which is a chaotic system as well. So, you may have noticed that weather forecasts have gotten more accurate the last few years, and that’s been because of machine learning. So, what’s been important is training the system after each prediction that didn’t come true. For instance, you said it was going to rain on a particular day and it didn’t; it actually rained four miles north or four miles south. So you put that new fact in, and then the system automatically reweights all the algorithms—because there are algorithms for every level of the atmosphere—to pinpoint what it got wrong, and then that improves it for the next time. Now, the exercise isn’t simple: Weather is the atmosphere. It’s 100 kilometers thick, it covers the whole earth, it’s fed by the oceans, and it’s always in motion.
But what’s important is that you’re constantly learning on the negative so that the algorithms reweight without losing what was the positive, and that’s how it gets higher and higher confidence in its predictions.
Bob Picciano (left) of IBM with David Kenny (right) at the IBM Insight Conference in 2015. Kenny was still with The Weather Company at the time.