Top-10 Application-Design Mistakes http://www.useit.com/alertbox/application-mistakes.html
It's hard to report on this because most mistakes are domain specific.
Do not change basic GUI standards. Doing so is like changing a language in the middle of a sentance. These standards are used to create consistency accross the web. When they are changed they confuse users. If Jakob's Law is "users spend most of their time on other websites," then Jakob's Second Law is even more critical: "Users have several thousand times more experience with standard GUI controls than with any individual new design."
When a user moves from one page to another or uses a utility, It is important that all Non-standard GUI controls stay consistent. Confusion results when applications use different words or commands for the same thing, or when they use the same word for multiple concepts in different parts of the application. Similarly, users are confused when things move around, violating display inertia.
"Affordance" means what you can do to an object. For example, a checkbox affords turning on and off, and a slider affords moving up or down. It is important that yo create a websight that includes perceived affordance only when you may accually use them. Including them with no action is meaningless.
Users appreciate feedback. This is a simple thing that makes users happy. Let them know the current state of a sight. Allow a way for them to know exactly what is going on.
Error Messages are a form of feedback. The most common guideline violation is when an error message simply says something is wrong, without explaining why and how the user can fix the problem. Such messages leave users stranded.
Users shouldn't have to enter the same information more than once. After all, computers are pretty good at remembering data. The only reason users have to repeat themselves is because programmers get lazy and don't transfer the answers from one part of the app to another.
Defaults help users in many ways. Most importantly, defaults can:
Most Web-based applications are ephemeral applications that users encounter as a by-product of their surfing. Even if users deliberately seek out a new app, they often approach it without a conceptual model of how it works. People don't know the workflow or the steps, they don't know the expected outcome, and they don't know the basic concepts that they'll be manipulating.
The worst instance of forcing users through a workflow without making the outcome clear is worth singling out as a separate mistake: Asking users to enter information without telling them what you'll use it for. This makes users not want to enter any information.
Too many applications expose their dirty laundry, offering features that reflect the system's internal view of the data rather than users' understanding of the problem space.
There are many principles above that will aid in creating well formed web sight. Most of these problems are resolved as the audience is taken into consideration. Also, know that less is more will help. Often times we get a little lazy and therefore neglect to think things through all the way. Have someone use the sight and watch them. Be prepared to see mistakes that are there.
February 29, 2008