“Complexity can be tamed, but it requires considerable effort to do it well. Decreasing the number of buttons and displays is not the solution. The solution is to understand the total system, to design it in a way that allows all the pieces fit nicely together, so that initial learning as well as usage are both optimal. Years ago, Larry Tesler, then a vice president of Apple, argued that the total complexity of a system is a constant: as you make the person's interaction simpler, the hidden complexity behind the scenes increases. Make one part of the system simpler, said Tesler, and the rest of the system gets more complex. This principle is known today as "Tesler's law of the conservation of complexity." Tesler described it as a tradeoff: making things easier for the user means making it more difficult for the designer or engineer.”