The Right Level of Abstraction
The best abstractions preserve human intention while hiding the machinery underneath.
The steering wheel is a perfect example of the right level of abstraction.
There are many other interfaces we could have chosen. A car could use a lever that you push left or right. It could use a joystick. It could even use a laser pointer that tells the car where to go, or a collection of random buttons.
Any of those interfaces could steer a car. What makes the steering wheel so good is that it turns the driver’s intention into one continuous, intuitive motion: left or right, a little or a lot. You just turn the wheel.
A perfect abstraction exposes exactly what the user needs and hides the rest of the machinery underneath. The steering wheel does exactly that. It preserves that simple motion while hiding the hydraulics, gears, and hinges between the wheel in your hands and the wheels on the road.