The Only Design Guidelines You'll Ever Need

For a variety of reasons, I've been thinking a lot about design and usability guidelines. I'm often asked, "What's the standard?" or "What's the best way to do such-and-such?" Well, as anyone who's worked in design knows, the answer is: It depends. Now, that's nothing new, but this morning I've formulated a new set of "über-guidelines", if you will.

1) If you have guidelines and they have been proven with users, follow them.
2) If you have guidelines and they have not been proven with users, follow them for consistency (and offer to prove--and improve--them).
3) If you do not have guidelines, develop and let users prove them.
4) If you do not have guidelines, nor the time to develop and prove them, the designer gets to pick. Just be consistent.

Beyond that, it's a matter of opinion, and the designer--who (by definition) is in the role of, um, "designer"--wins.

Usability and Forms: Default Values

I have a client with whom I've had several lively debates about when to use default values in a complex form. I have searched for studies, writings or heuristic references with no luck. In the mean time, until someone points to better work that someone else has done, I offer the following suggestions for when default values are appropriate:

1. If you are trying to save the user mouse-clicks.
   If you don't care because the form isn't complex enough or you don't have the time or resources to define and implement default values, then don't bother.
2. If the user of the system would most likely select the option chosen.
   If 80% of your audience is U.S., then make U.S. the default with the option to change. (Don't, however, put U.S. on the top, if you care about having an equitable, global form.)
3. If the user is not being asked to make a declaration for legal or compliance purposes.
   Don't default them to the "correct" answer if you want them to make an explicit electronic declaration. Don't default them to the "incorrect" answer, either to make them pick the "correct" answer. A recent usability test I conducted on just such a page showed us that users expect a defaulted answer to be the "correct" answer.
4. If the default option is the "right" option.
   See 3. above.

Additionally, user expectations would be that, if you are providing default values for some controls in a form, you would provide default values for most similar controls in the form (for example, all yes/no combinations or all dropdown selectors would behave similarly).