Contingency design and error tolerance

Discussion articles

  • Contingency design: maximising online profitability by helping people when things go wrong
    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. This white paper explains what contingency design is and how to evaluate your site's contingency design. It also includes 20 rules for improving and ranking the contingency design at your site. It also shows real-world examples of good and bad contingency design as well as side-by-side comparisons of well-known sites handling common visitor problems so you can examine this crucial usability issue in action.

  • Error message guidelines
    Established wisdom holds that good error messages are polite, precise, and constructive. The web brings a few new guidelines: Make error messages clearly visible, reduce the work required to fix the problem, and educate users along the way.

  • Error message guidelines
    Users often misunderstand popup errors, administrators cannot easily understand event log messages, and technical support receives many calls as a result of confusing error messages. These guidelines, from Microsoft, will help you write more useful error messages.

  • How to handle the page not found error
    Every site should handle the page not found error gracefully.

  • Polite computers win users hearts and minds
    Computer glitches would be a lot less annoying if the machines were programmed to acknowledge errors gracefully when something goes wrong, instead of merely flashing up a brusque "you goofed" message.

  • The cranky user: could you repeat that in English?
    Frequently, error messages are totally uninformative--or, worse, just plain wrong. Here, we look at how meaningful error messages can make it easier for users to correct problems without having to rely on technical support, and how poorly chosen messages can turn users into ex-users.

  • The perfect 404
    Welcome to the world of the Error 404 page. You’ve requested a page, either by typing a URL directly into the address bar or clicking on an out-of-date link, and you’ve found yourself in the middle of cyberspace nowhere. A user-friendly website will give you a helping hand while many others will simply do nothing, relying on the browser’s built-in ability to explain what the problem is. We can do better than that, can’t we?

  • Useful "page not found" error messages
    Ever encountered a "404 error" message on a site? Also known as a "page not found" error, it can really annoy visitors. Some of these folks may never return to your site. If you don't handle these people with care, you could drive important traffic away from your site. Now, you really don't want to do that, do you?

Books and book reviews

  • Defensive Design for the Web
    After reading Defensive Design for the Web, I think of potential problems as places to learn more about the user and to make the site better.