While a certain level of trust is needed for autonomous cars and smart technologies to reach their full potential, these technologies are not infallible—hence why we’re supposed to keep our hands on the wheel of self-driving cars and follow traffic laws, even if they contradict our map app instructions. Recognizing the significance of trust in devices—and the dangers when there is too much of it—Erin MacDonald, assistant professor of mechanical engineering at Stanford University, researches whether products can be designed to encourage more appropriate levels of trust among consumers.