Water and Stone

Over the last few years, usability practice has begun to take on a new maturity. Systems have become more formalized, practices more standardized, and in the process certain principles have risen to prominence.  To get you thinking about what it means to create usable applications, here’s a list of six basic principles which should be applied when you are building software-based systems.

(1) Consistency & Reuse
A good system will reduce the need for users to rethink the system by consistently reusing external and internal systems and behaviors.

A good way to approach building computer applications is to stick with the conventions of the computer platform. People are familiar with buttons, scroll bars, combo boxes, etc., so use them. You don’t have to render everything as a stylized graphic to have an attractive site. Buttons, for example, should look like buttons and should bear labels users have seen before. There is no good business reason to re-invent the wheel, simply because you can. Once a convention is applied, do not vary from it without reason and when you vary from it, make it clearly different. Reinforce your conventions throughout the application and you will find that users are able to navigate and move easily.

(2) Tolerance
A good system cuts down on terminal errors by building in tolerance for foreseeable misuse and reduces the cost of errors by allowing users the option to redo or undo the offensive action.

While supporting “undo” can be challenging on the Web, it is not impossible and should certainly be a part of any key process, like a multi-part form, or a shopping cart. One of the frustrations most commonly cited by users is the loss of data on forms when they go “back” to add information or correct an error. Make sure your programmers build sites that persist data to allow for effective “undo” and re-do”.

(3) Feedback
A good system will keep users informed of changes in state or condition, or of errors, in clear, unambiguous language, informing the user of the range of options available (if any).

When the Macintosh first appeared (128K!) I rushed out and bought one. While I loved the interface and the usability of the device, it completely fell down when it came to error reporting. When my little gray box would crash, it would produce a frowning face and spit out an utterly useless error code in the form of a meaningless string of digits. There was no clue why it had crashed, or what could be done. (Users eventually learned that the liberal application of a straightened out paper clip to the obscure reset button was their only recourse.) Apple has finally gotten that fixed, but it took them years (and cost them lots of frustrated users).

(4) Jakob’s Law of the Web User Experience
Users spend most of their time on other sites, so that's where they form their expectations for how the Web works.

Well, that statement may be a truism, but it’s worth repeating. From a business perspective Jakob is right: We should be building things people recognize and can navigate without difficulty. There is a reason why Amazon, Yahoo, Excite, eBay, and all those other large sites share common elements – the interface is familiar to users and works with the wide variety of computers and browsers in the market. If you want your site to be accessible to the widest audience possible, learn from the Big Boys and follow their approach.

(5) Organize Purposefully
Group like things together; separate unlike things in a meaningful manner; keep all the necessary tools and materials visible; don't clutter the interface with extraneous information.

Seems obvious, but so many sites I visit are a visual train wreck. Frankly, I am not interested in spending 5 minutes trying to find the button that takes me to where I want to go. Clean out the extraneous junk – remember, what doesn’t add to your message detracts from it.

(6) Keep the User Focused
A good system allows a user to answer these three questions at any stage in the process: (1) Where I am? (2) Where I should go next? (3) How do I get back to where I was?

While this last principle seems to be limited in application to processes, say a shopping cart, in fact it should be applied across your site. New users will thank you, and experienced users will use the system more efficiently. You will find that if you adhere to this final simple principle, users will describe your system as “intuitive” or “user-friendly”.

Hopefully these points will give you a starting point for your own usability analysis. In the next installment in this series we will look at the value of usability in dollars and cents.