Top Ten Mistakes in Web Design

1. Bad Search

2. PDF Files for Online Reading

Users hate coming across a PDF file while browsing, because it breaks their flow. Even simple things like printing or saving documents are difficult because standard browser commands don't work. Layouts are often optimized for a sheet of paper, which rarely matches the size of the user's browser window. Bye-bye smooth scrolling. Hello tiny fonts.

3. Not Changing the Color of Visited Links

A good grasp of past navigation helps you understand your current location, since it's the culmination of your journey. Knowing your past and present locations in turn makes it easier to decide where to go next. Links are a key factor in this navigation process.

4. Non-Scannable Text

A wall of text is deadly for an interactive experience. Intimidating. Boring. Painful to read.

5. Fixed Font Size

CSS style sheets unfortunately give websites the power to disable a Web browser's "change font size" button and specify a fixed font size. About 95% of the time, this fixed size is tiny, reducing readability significantly for most people over the age of 40.

6. Page Titles With Low Search Engine Visibility

Search is the most important way users discover websites. Search is also one of the most important ways users find their way around individual websites. The humble page title is your main tool to attract new visitors from search listings and to help your existing users to locate the specific pages that they need.

7. Anything That Looks Like an Advertisement

Selective attention is very powerful, and Web users have learned to stop paying attention to any ads that get in the way of their goal-driven navigation. (The main exception being text-only search-engine ads.)

Unfortunately, users also ignore legitimate design elements that look like prevalent forms of advertising. After all, when you ignore something, you don't study it in detail to find out what it is.

Therefore, it is best to avoid any designs that look like advertisements. The exact implications of this guideline will vary with new forms of ads; currently follow these rules:

• banner blindness means that users never fixate their eyes on anything that looks like a banner ad due to shape or position on the page
• animation avoidance makes users ignore areas with blinking or flashing text or other aggressive animations
• pop-up purges mean that users close pop-up windoids before they have even fully rendered; sometimes with great viciousness (a sort of getting-back-at-GeoCities triumph).

8. Violating Design Conventions

Consistency is one of the most powerful usability principles: when things always behave the same, users don't have to worry about what will happen. Instead, they know what will happen based on earlier experience. Every time you release an apple over Sir Isaac Newton, it will drop on his head. That's good.

The more users' expectations prove right, the more they will feel in control of the system and the more they will like it. And the more the system breaks users' expectations, the more they will feel insecure. Oops, maybe if I let go of this apple, it will turn into a tomato and jump a mile into the sky.

Jakob's Law of the Web User Experience states that "users spend most of their time on otherwebsites."

This means that they form their expectations for your site based on what's commonly done on most other sites. If you deviate, your site will be harder to use and users will leave.

9. Opening New Browser Windows

Opening up new browser windows is like a vacuum cleaner sales person who starts a visit by emptying an ash tray on the customer's carpet. Don't pollute my screen with any more windows, thanks (particularly since current operating systems have miserable window management).

10. Not Answering Users' Questions

Users are highly goal-driven on the Web. They visit sites because there's something they want to accomplish -- maybe even buy your product. The ultimate failure of a website is to fail to provide the information users are looking for.