The author points out that 1st grade Japanese students, many who score better than some US public school students, actually spend less time in school than their US counterparts. While the Japanese students undergo intensive instruction, they have twice as many recesses and have shorter school days for their youngest students. More time is allowed for peer play at home, socialization, and other activities (such as music lessons). Time well spent.
In one of our trainings the instructor said that 7 minutes is typically the amount of time that people are able to focus intently on a given thing before they need a bit of a break or change.
I've been using the 7 minutes idea in my classroom during the last few months of the school year. I now try to deliver my lessons in 7 minutes segments. I don't give directions for longer than 7 minutes without some sort of break. I try to move things along so that my instructional time is shorter - then take a few questions and if clarification or more instruction is needed, I go from there. The kids had been very talkative most of the time bug since I've been using the "7 minutes" the work productivity has gone way up. Here's the approach I use: I have a timer on my computer and I project the image on an overhead screen. I tell the kids that for 7 minutes there is to be no talking and no questions (unless of course they need information to continue working). After the 7 minutes, I give them 3 minutes of a more causal work time. They can take at least one min to stretch, relax (especially helpful if we are drawing or coloring) shake loose their tired hands, and talk casually to people at their tables. They can share work and ask questions at this time too. They are to keep working but it's not as intense as is the 7 minutes. If after 7 minutes of instruction time, I encourage students to discuss what they just heard from me. During individual work time, I allow for quiet talking and sharing of work and ideas.This seems to be working. I have fewer management problems using this approach. The kids seem to like the timer as they know they will get a break and they know when it's coming.
Timers I use:
One to download (I mainly use this one - it's the same timer used by the instructor in one of our school trainings. (direct download here: screentimerpc.zip )