"There was a time when more of us knew how to change the oil and change a timing belt, keep an engine running and fix the brakes. Cars got more complicated and we got less mechanical, but one thing hasn’t changed: if you are buying a used car, you can’t trust the seller to tell you what’s wrong with it. If you’re a government official buying an algorithm, whether marketed as predictive analytics, AI, or machine learning, the same thing is true. It’s great if you have a mechanic you trust. It’s even better if you also have some idea of what to look for yourself."