Data validation techniques - Interactive, Preflight Checklist, etc.

Question

I am working on a form filling program and I'm looking for suggestions on implementing data validation.

I'm considering a two-phase approach:

• Interactive - after user enters data and attempts to move to the next field, flag invalid data with something non-obtrusive, like a balloon message but let the user continue on.
• Preflight Checklist - Once the form is filled and the user attempts to print/send it, re-validate the form, notify user of errors and refuse to continue until corrections are made.

Any other ideas, suggestions?

Answer 1

I would always recommend validating at the server as well.

Otherwise, what you describe is what I typically see. Oh... and don't flag a required field as invalid if a user tabs through it, unless it's still blank when they submit, but if they enter "wrong" data into a field, indicate it immediately, as you describe.

Answer 2

OK, if you are asking about user experiace, then i would apply both 1 and 2.

As users input fields, highlight fields, that are required, incorrect with colours/icons (no blloons, they are in the way). Icons can then be clicked for explanation of why it is incorrect.

Also validate the form at the end, before submit, and highlight the incorrect fields/required missing fiels, but try to avoid step by step acceptance (click ok, and message per field missing, incorrect).

You could rather then have a display that tells the user the messages, but dont remove this, otherwise you are back where you started from, click and go.