Human machine blur testing method

A method of validating a design for a graphical user interface of a motor vehicle, the method comprising:

• creating a tentative design for the graphical user interface;
• producing a blurred version of the tentative graphical user interface design, the producing including providing a blurring lens over the tentative graphical user interface design;
• wherein the blurred version of the tentative graphical user interface design is out of focus;
• testing the blurred version of the tentative graphical user interface design for readability by showing a test user the tentative graphical user interface design at a distance and lighting conditions under which a driver would view the graphical user interface in the motor vehicle, wherein if it is determined that the blurred version of the tentative graphical user interface design is not readable by the test user saying which elements of the tentative graphical user interface design the test user had trouble identifying, then the graphical user interface is redesigned and the producing and testing steps are repeated for the redesigned graphical user interface;
• and
• after the blurred graphical user interface design has been determined to be readable, then making a first physical prototype of the graphical user interface.