The UX of LEGO Interface Panels⁠↗

It was the psychologist Alphonse Chapanis who first suggested that the high rate of crash landings might be the fault of poor interface design. The adjacent landing gear and flap control knobs were identically shaped. The pilots never stood a chance.

Shape coding is one approach to differentiation, but there are many others. Colour coding is perhaps the only one to break into our everyday vocabulary, but we can add four more: size, texture, position and operation coding. Together these six are our allies in the design of error-proof interfaces.

LEGO use the Soviet schematic approach for their fantasy orientated designs, because schematics are superb at providing a mental model of the inner workings of an alien system.