什么— Definition of Usability

Usability is a质量属性that assesses how easy user interfaces are to use. The word "usability" also refers to methods for improving ease-of-use during the design process.

Usability is defined by5质量组件:

  • Learnability:用户在第一次遇到设计时完成基本任务有多容易?
  • 效率:一旦用户学会了设计,他们能以多快的速度执行任务?
  • Memorability:When users return to the design after a period of not using it, how easily can they reestablish proficiency?
  • Errors:有多少errors用户是否犯了错误,这些错误有多严重,以及从错误中恢复的容易程度如何?
  • Satisfaction:使用这种设计有多愉快?

There are many other important quality attributes. A key one is效用,which refers to the design's functionality: Does it do what users need?


  • 定义Utility=是否提供features you need.
  • 定义Usability=如何easy & pleasant这些功能是要使用的。
  • 定义Useful=usability + utility.


在网络上,可用性是生存的必要条件。如果一个网站很难使用,人们离开. 如果homepage没有明确说明一家公司提供了什么,用户可以在网站上做什么离开. 如果用户在网站上迷路了,他们离开.If a website's information is hard to read or doesn't answer users' key questions, they离开.Note a pattern here? There's no such thing as a user reading a website manual or otherwise spending much time trying to figure out an interface. There are plenty of other websites available; leaving is the first line of defense when users encounter a difficulty.

The first law ofecommerce如果用户不能findthe product, they cannot购买it either.

为了内部网,可用性是员工生产力.Time users waste being lost on your intranet or pondering difficult instructions is money you waste by paying them to be at work without getting work done.

Current best practices call for spending about10% of a design project's budgeton usability. On average, this will more than网站所需质量指标的两倍(屈服于改善得分略低于内联网质量指标的两倍。对于软件和物理产品,当您在设计过程中强调可用性时,改进通常较小,但仍然是实质性的。

内部设计projects, think of doubling usability as cutting training budgets in half and doubling the number of transactions employees perform per hour. For external designs, think of doubling sales, doubling the number of registered users or customer leads, or doubling whatever other KPI (key performance indicator) motivated your design project.

怎么to Improve Usability

There are many methods for studying usability, but the most basic and useful isuser testing,which has 3 components:

  • Get hold of some代表用户,such as customers for an ecommerce site or employees for an intranet (in the latter case, they should work outside your department).
  • 要求用户执行representative tasks与设计。
  • 观察用户做了什么,他们在哪里成功了,他们在用户界面上遇到了什么困难。闭嘴让用户说话.

单独测试用户,让是很重要的them solve any problems on their own. If you help them or direct their attention to any particular part of the screen, you have contaminated the test results.

To identify a design's most important usability problems,testing 5 usersis typically enough. Rather than run a big, expensive study, it's a better use of resources to run many small tests and revise the design between each one so you can fix the usability flaws as you identify them.迭代设计is the best way to increase the quality of user experience. The more versions and interface ideas you test with users, the better.

User testing is different from焦点小组,which are a poor way of evaluating design usability. Focus groups have a place in market research, but to evaluate interaction designs you must closely observe individual users as they perform tasks with the user interface.Listening to what people say这是一种误导:你必须观察他们的实际行动。


Usability plays a role in each stage of the design process. The resulting need for multiple studies is one reason I recommend making individual studies fast and cheap. Here are the main steps:

  1. Before starting the new design,test the old design找出你应该保留或强调的好部分,以及给用户带来麻烦的坏部分。
  2. 除非你在内网上工作,test your competitors' designsto get cheap data on a range of alternative interfaces that have similar features to your own. (If you work on an intranet, read theintranet design annual向其他设计学习。)
  3. 进行field studyto see how users behave in their natural habitat.
  4. 制造paper prototypesof one or more new design ideas and测试他们. 您在这些设计思想上投入的时间越少越好,因为您需要根据测试结果对它们进行更改。
  5. 优化设计思想,通过multiple iterations,逐渐从低保真度原型设计转向在计算机上运行的高保真表示。测试每个迭代。
  6. 检查与之相关的设计1Manbetx 无论是你自己的早期研究还是发表的研究。
  7. Once you decide on and implement thefinal design,test it again. Subtle usability problems always creep in during implementation.

Don't defer user testing until you have a fully implemented design. If you do, it will be impossible to fix the vast majority of the critical usability problems that the test uncovers. Many of these problems are likely to be structural, and fixing them would require major rearchitecting.

The only way to a high-quality user experience is to start user testing early in the design process and to keep testing every step of the way.


If you run at leastone user study per week,值得建立一个专门的可用性实验室。然而,对于大多数公司来说,在会议室或办公室里进行测试是可以的——只要你能关上门以防分心。重要的是,你要抓住真正的用户,在他们使用设计的时候和他们坐在一起。记事本是你唯一需要的设备。