When I worked for a consultancy in early internet days I also often repeated "the customer doesn't …
… When I worked for a consultancy in early internet days I also often repeated "the customer doesn't know what they want until they see what they don't want". People weren't used to web GUIs and there weren't the common patterns we see today, so it wasn't until they had a half working version they could actually give feedback, so getting early feedback was essential to reduce the frustrating of building something that is immediately changed. It still applies today but less to do with usage patterns and more to do with missing requirements the customer forgot to tell you about.
Original discussionGUIs are built at least 2.5 times149 source comments · at import