Guerrilla HCI: Using Discount Usability Engineering to Penetrate the Intimidation Barrier
http://www.useit.com/papers/guerrilla_hci.html

Nielsen, Jakob
Alertbox
1994

Abstract:

When asking how many usability specialists it takes to change a light bulb, the answer might well be four: Two to conduct a field study and task analysis to determine whether people really need light, one to observe the user who actually screws in the light bulb, and one to control the video camera filming the event. It is certainly true that one should study user needs before implementing supposed solutions to those problems. Even so, the perception that anybody touching usability will come down with a bad case of budget overruns is keeping many software projects from achieving the level of usability their users deserve.