Estimating Stories

Purpose

The ability to estimate how long a story will take is one of the keys to being able to plan your project. The purpose of this exercise was to learn how to estimate a user story.

Description

We used the user stories from the previous exercise in this exercise too. The participants were given 45 minutes to estimate all the stories. This gave them a little more than one minute per story.

Events

By this time the participants were used to the chaos. Most of them just started doing the estimates, although they did have questions about what kinds of units they needed to use. We told them they could use any units that they wanted.

At the end of the time limit, all the groups had an estimate for how long they thought the application would take to implement. The estimates had a fairly large range, although all the groups were fairly certain that their estimates were correct, plus or minus 10%.

Just as in the previous exercise, where groups had difficulty in writing acceptance tests for certain stories, the same stories were hard to test. In both exercises, the reason for the difficulty tended to be that the story was too large or too vague.