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.
Respect the user's preferences and let them resize text as needed. Also, specify font sizes in relative terms -- not as an absolute number of pixels.
固定字体大小。CSS可以控制字体的小大，我们大多在使用这一点使文字变为好看的宋体9px，但忽略了超过40岁用户的感受。同时也禁止掉了浏览器的“改变字体大小”的功能。我老爸一直问我，这个站文字太小了，在看到不能改变的时候，我只能告诉老爸使用Maxthon的放大页面功能。
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.
The page title is contained within the HTML <title> tag and is almost always used as the clickable headline for listings on search engine result pages (SERP). Search engines typically show the first 66 characters or so of the title, so it's truly microcontent.
Page titles are also used as the default entry in the Favorites when users bookmark a site. For your homepage, begin the with the company name, followed by a brief description of the site. Don't start with words like "The" or "Welcome to" unless you want to be alphabetized under "T" or "W."
For other pages than the homepage, start the title with a few of the most salient information-carrying words that describe the specifics of what users will find on that page. Since the page title is used as the window title in the browser, it's also used as the label for that window in the taskbar under Windows, meaning that advanced users will move between multiple windows under the guidance of the first one or two words of each page title. If all your page titles start with the same words, you have severely reduced usability for your multi-windowing users.
Taglines on homepages are a related subject: they also need to be short and quickly communicate the purpose of the site.
低搜索引擎可视性的页面标题。这一句翻译的不好，讲的是SEO的相关问题，但我认为也是措辞的问题，简洁的能让用户一眼就明白即可。
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).
任何东西都看起来向广告。可用性和商业还是有冲突的，当我们抛开商业模式谈广告，这是一门学问。这里探讨的是如何把广告变的更好的问题，我听说yahoo的广告是按点击率来算业绩的，我想，未来国内也是这样，很可能会加上一点，用户体验更爽。但至少目前的广告不应该是两帧或三帧闪来闪去。
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 other websites."
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.
违反设计习惯。这里尼尔森谈的是继承的问题，我相信老大在深圳UPA会上的讲话，比如：QQ的消息声音是不能改变的。这就是一个习惯的问题，已经有先前的习惯了，违反这个习惯是要负出代价的，当然，如果你有足够的资金的化当我没说。前一段也有小案例，一个朋友把网站首页放到浏览器的右边了，我说这样的突破太大，很多用户会找不到的。这是一个设计习惯，也是一个用户习惯的问题。
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).
Designers open new browser windows on the theory that it keeps users on their site. But even disregarding the user-hostile message implied in taking over the user's machine, the strategy is self-defeating since it disables the Back button which is the normal way users return to previous sites. Users often don't notice that a new window has opened, especially if they are using a small monitor where the windows are maximized to fill up the screen. So a user who tries to return to the origin will be confused by a grayed out Back button.
Links that don't behave as expected undermine users' understanding of their own system. A link should be a simple hypertext reference that replaces the current page with new content. Users hate unwarranted pop-up windows. When they want the destination to appear in a new page, they can use their browser's "open in new window" command -- assuming, of course, that the link is not a piece of code that interferes with the browser抯 standard behavior.
打开新浏览器窗口。这个问题不想多说，各个业务是不同的，应该是有区分的，但在流程中不应该打开新窗口，这个是中断了用户的流程。
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.
Sometimes the answer is simply not there and you lose the sale because users have to assume that your product or service doesn't meet their needs if you don't tell them the specifics. Other times the specifics are buried under a thick layer of marketese and bland slogans. Since users don't have time to read everything, such hidden info might almost as well not be there.
The worst example of not answering users' questions is to avoid listing the price of products and services. No B2C ecommerce site would make this mistake, but it's rife in B2B, where most "enterprise solutions" are presented so that you can't tell whether they are suited for 100 people or 100,000 people. Price is the most specific piece of info customers use to understand the nature of an offering, and not providing it makes people feel lost and reduces their understanding of a product line. We have miles of videotape of users asking "Where's the price?" while tearing their hair out.
Even B2C sites often make the associated mistake of forgetting prices in product lists, such as category pages or search results. Knowing the price is key in both situations; it lets users differentiate among products and click through to the most relevant ones.
不回答用户的问题。最痛心的是这一点，有时候并不是可用性的问题，商业上不能做，不能告诉用户的观念占据了很大的程度。尼尔森在这里列举了购买产品的例子，在产品的页面中，用户往往不能完全了解产品，没有把握住用户的心理是最失败的部分。我常和同事说flickr在删除相册夹有一个很好的提示，对心理抓的很准，而更巧妙的是，这个提示在操作中完成。
尼尔林从一九九六年就开始在alertbox里写Top ten，有兴趣的可以看下以前的内容。
Top Ten Mistakes in Web Design(1996)
Top Ten Mistakes in Web Design(1999)
Top Ten Mistakes in Web Design(2002)
Top Ten Mistakes in Web Design(2003)
Top Ten Mistakes in Web Design(2005)
来源：新浪科技 作者：xiaoxiao
