I was researching about Extreme Programming, and started reading a book by Kent Beck called Extreme Programming Explained. There he mentioned practices and principles one of which confused me. It said that iterations must short.
If iterations are good, we'll make the iterations really, really short - seconds and minutes and hours, not weeks and months and years (Extreme Programming Explained - Preface
Later on in the same book, Kent Beck uses iterations in weeks:
Within a release, XP uses one- to four-week iterations of customer-requested features for fine-grained feedback about progress. (Extreme Programming Explained - Chapter 1)
The glossary again mentions a 1-4 week iteraiton:
A one- to four-week period. At the beginning, the customer chooses the stories to be implemented in the iteration. At the end the customer can run their functional tests to see if the iteration succeeded.
(Extreme Programming Explained - Glossary)
However when I read on the extreme programming website, it says that iterations are 1 - 3 weeks long. However, I found a video (starting at time 7:09) where it mentions iterations in days, minutes, and seconds.
In Extreme Programming, how long are iterations and how do they work? Does an iteration work on 1 user story for 2 weeks? That seems alot. One of the reasons this confuses me is because Scrum completes multiple user stories in one sprint which last for 2 weeks. When I further researched about that it said that developers prefer 2 week iterations. So which one is it? Am I confusing it with something else?