I was wondering about the default duration of a pomodoro (25 minutes). In the PDF on the Pomodoro technique(1) it says:
The length of a Pomodoro, 25 minutes, seems short enough to make it possible to resist being distracted by various kinds of interruptions.
This seems to suggest that 25 minutes is just a random duration taken by the author which happens to work for him and which many people now seem to use. Are there any scientific studies that indicate that 25 minutes is the optimal time (for most people and most tasks) for a pomodoro?
(1) The original link is broken. It seems the PDF is no longer available on the PomodoroTechnique.com, most likely because they are now selling a book. The old PDF can still be found here