Pretend, for a moment, that you are building a home. You have laid its foundation, raised its walls, and now it is time to install the kitchen. As a particularly handy individual, you have assembled your own stove, with only the control knobs remaining. How will you arrange them? Most stovetops place burners in a 2×2 square, with their control knobs positioned horizontally in one row. If the knobs were to be also arranged in a 2×2 square, your user experience would be far smoother. The necessary mental mapping of knob to burner would be simpler, and you could easily turn the correct knob for the burner you wanted. However, this choice raises issues of physical design, as the knobs would no longer fit neatly in a row in front of the burners.