Developers and users perspectives. If youre a software developer, you need to understand the perspective of people who use your software.
I ran across a good, small example of the difference between the two perspectives, via an email from a NetNewsWire user. I mention it because it might be illustrative of one of the ways developers and users see things differently.
It also illustrates one law of UI design: dont let the logical and correct thing get in the way of the right thing.
Heres the example:
When you import an OPML subscriptions file into NetNewsWire, if the file is a valid OPML file but contains no subscriptions, NetNewsWire doesnt report an error.
Its logical, no? Its a valid subscriptions file, and NetNewsWire successfully imported zero out of zero subscriptions.
But its not the right thing, because someone using the software is left wondering what the hell just happened. An error message that explains that the subscriptions file contained no subscriptions would be the right thing to do.
So heres another law of UI design: while developers see zero as just another number, users often see zero as an error. [inessential.com]