"Here’s a question that I get asked quite often: “Should we put ‘OK’ button to the left or the right of the ‘Cancel’ button?”
A common variant is to ask the same question with ‘Back’ or ‘Previous’ instead of ‘Cancel’, and to maybe include ‘Next’ in the mixture.
A SIMPLE QUESTION, A COMPLEX ANSWER
I’d love to tell you: put OK on the left. Or on the right. Or something else that’s easy to say and easy to remember. Like so much in forms, the simple answer isn’t really appropriate. And yet, who needs another ‘it depends’? We’ve got far too many of them in usability. The truth, of course, is that ‘it depends’ is the right answer yet again. But we’ll avert our eyes from that and I’ll try to give a few rules here.
RULE 1: LOOK AT OTHER FORMS
The first point is to find out what other forms your users are working with and see where those other programs put their buttons. For example, years ago Jakob Nielsen pointed out that most users spend most of their time on web sites other than yours. Or if you’re creating a program that will be used alongside Microsoft Office applications, then your users are likely to expect your program to follow their conventions. It does get a bit tricky if your users swap regularly between Mac and PC, because unfortunately the two operating systems have conflicting guidelines. Then you’ll have to think carefully about which one you’re going to follow – preferably, after doing some research on what your users do and which applications matter most to them.
RULE 2: PUT BUTTONS AT THE END OF THE CONVERSATION
The big deal with forms is that they ask users one or more questions, after which the user presses a button to say ‘I’m done with my turn in this conversation’. The conversational turn is handed over to the computer to do something. There needs to be a button. It’s usually called ‘OK’, ‘Send’, ‘Submit’ or ‘Next’. The crucial point is that it goes at the end. One common mistake I’ve seen: putting important instructions, or even whole questions, after that final button. A position that’s invisible to users. Don’t do it.
RULE 3: DECIDE WHETHER THE BUTTON IS NECESSARY
A while ago, I wrote a column: “The Piece of HTML created just for me: Reset”. My theme was that ‘Reset’ buttons are rather handy for the forms consultant who regularly hunts for forms on web sites, fills them in and then wants to discard her entries. Sadly, the majority of them are at best useless and at worst deeply annoying for other users. Do you really need other buttons? Do your users want to discard all their work? If you don’t really need a button, then get rid of it." (Continued via Usability News, Caroline's Corner) [Usability Resources]