There's a big problem with AI: even its creators can't explain how it works

The car's underlying AI technology, known as deep learning, has proved very powerful at solving problems in recent years, and it has been widely deployed for tasks like image captioning, voice recognition, and language translation. The resulting program, which the researchers named Deep Patient, was trained using data from about 700,000 individuals, and when tested on new records, it proved incredibly good at predicting disease. But it was not until the start of this decade, after several clever tweaks and refinements, that very large--or "deep"--neural networks demonstrated dramatic improvements in automated perception. Deep learning has transformed computer vision and dramatically improved machine translation.