Estimation Techniques
There are a number of estimation techniques that a Scrum Master can use to assist the team in sizing each story.
Planning Poker
The most popular technique is planning poker. This method involves handing out a set of cards, usually containing a series of Fibonacci numbers, to each team member. The Product Owner then takes each story in turn and describes it in as much detail as possible. Following this, each team member picks the card which they think is the correct size for that particular story and places the card face down in front of them.
When everyone has selected their card, they are turned face up to see what the scoring is. If there is a wide variation in scoring, the lowest scorer and the highest scorer are normally asked to give their reasons, and then a re-score is carried out. The Scrum Master then assists with taking the average and marks it down as being the size of the story before moving on to the next item on the list.
This estimation method can be used when the team seems to be spending too much time trying to get to a very exact number of story points, possibly because some team members are equating this with the number of hours required to complete the work. When using t-shirt sizing, estimates are selected from a range of extra-small, small, medium, large, extra-large, or double extra-large. While this technique can help in situations where people are becoming too analytical and getting bogged down in the details, it does require additional effort on the Scrum Master’s part, as he/she will then need to assist with translating the t-shirt sizes into the number of story points at a later stage when the planning session is over. It tends to be more common to use this technique when people are relatively new to agile, or when a team has been newly formed. Over time, as the team gels together, it would be more appropriate to move to a somewhat more sophisticated technique like planning poker.
Recommended Further Reading
The following materials may assist you in order to get the most out of this course: