Contingency design is design for when things go wrong . It’s the error messaging, graphic design, instructive text, information architecture, backend system, and customer service that helps visitors get back on track after a problem occurs.
Whitepaper on 37signals.com
Defensive design is inspired by the concept of ‘defensive driving’ (that is , recognizing potential accident situations developing and taking advance measures to avoid them). (…) Site builders must constantly search for trouble spots that may cause visitors confusion and frustrations.
Examples of successful contingency design:
- An error message that clearly explains how to fix the problem
- A form field that prevents a visitor from entering too many characters
- A form that validates responses before they accepted
- Customised ‘Page not found’ screen that explains the problem and helps people get to the desired page
- Contextual help (definitiojns and inline FAQs that answer questions on the spot
- Login help (for instance ‘Forgot your Password? Click here’)
- Help copy that doesn’t require a dictionary or technicalk manual to understand
- FAQs that solve the most common problems that plague customers
- A smart search engine that understands misspellings and other common errors
- Email notification for the return of an out-of-stock item
Matthew Linderman with Jason Fried (37signals): Defensive design for the Web (2004), New Riders