The following is a reference to workplace related design but you can see how it has implications to any design effort, particularly when we want to enable a good user experience.
In a classic narrative Mark S Sanders and late Ernest J McCormick, Human Factors Psychologist and Industrial Psychologist respectively, recall one of their conversations with a few engineers regarding nuclear power plant displays’ console design. One of the authors, as a consultant, met with two engineers to discuss the console. Additional background to the following conversation was that there was a scale drawing of a preliminary design with no mock-up (and no intent to create one either). “The consultant asked the engineers to ‘walk him through’ the console so he could become familiar.”
Here is the verbatim of the conversation Sanders and McCormick (1993) wrote in their book:
Engineers: These are the six XYZ concentrate indicators.
Consultant: What is the operator’s task here? Does the operator have to read a specific value, compare values between indicators, or use these indicators while manipulating controls?
Engineers: We really don’t know – that is Operations’ responsibility. We will see that someone from Operations come in later to answer your questions.[The Operations office was 25 miles from the office where the preliminary design was developed. And I believe there was no Internet, leave alone the Lync, at that time.]
Engineers: Let’s continue. This is a digital readout that directs the operator’s sequence of actions.
Consultant: How does the operator use that? What displays and controls are referred to by the readout? How much time does the operator have to respond to the display?
Engineers: We really don’t know – that is Operations’ responsibility.
Consultant (now becoming a little irritated): Exactly what did the two of you have to do with this console anyway?
Engineers: We designed it! Each of us started at a different end, and we laid out the displays going across. We then compared the layouts and selected the parts from each we liked the best.
Consultant: I think this would be a good time for a coffee break.
Sanders, M.S., & McCormick E J (1993). Human Factors in Engineering and Design (7th ed.). McGraw-Hill, Inc.