从一个已有用户故事开始

Feature: Add a movie to RottenPotatoes
  As a movie fan
  So that I can share a movie with other movie fans
  I want to add a movie to RottenPotatoes database

用户故事的一般形式Connextra格式

Feature name 
  As a [kind of stakeholder],
  So that [I can achieve some goal], 
  I want to [do some task]
软件功能名称 
  作为 [角色],
  为了 [我能达到某些目标], 
  我想要 [做一些事情]

里面的动作主体,即利益相关者,或者是系统角色。这三句话的顺序可以改变,但必须出现。比如

软件功能名称 
  作为 [角色],
  我想要 [某些功能],
  以便 [我能获得某些价值], 

用户故事的SMART准则

比较下面两个

Feature: User can search for a movie (vague)
Feature: User can search for a movie by title (specific)

有确定的结果,作为软件即可测试。试比较:

Feature:  RottenPotatoes should have good response time (unmeasurable)
Feature:  When adding a movie, 99% of Add Movie pages 
          should appear within 3 seconds (measurable)

大小适中,在一个迭代周期,1~2周内完成。故大小可能是几小时或者几天,不超过5天。不然就要拆分。