A bad website is like a grumpy salesperson.

Windows '98 is so similar to Windows '95 because Apple hasn't invented anything worth copying since 1995.

The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.

Inadequate use of usability engineering methods in software development projects have been estimated to cost the US economy about $30 billion per year in lost productivity.

The best Web sites are better than Reality.

Ultimately, users visit your website for its content. Everything else is just the backdrop.

Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.