By the numbers - Discipline
Classroom behaviour has been the target of several recent initiatives in the UK and US.
In England, Michael Wilshaw, the chief inspector of schools, has said that inspectors scrutinising teacher training courses will now pay more attention to how trainees are being prepared to manage behaviour and instil discipline.
And the US Department of Education last month released new guidance after concerns were raised that discipline was not being applied equitably.
The advice is linked to the Supportive School Discipline Initiative, which offers alternatives to exclusion to encourage institutions to keep students in school.
Exclusions are used extensively in some areas. Education secretary Arne Duncan revealed at the launch of the guidance that South Carolina suspended one in eight of its students during 2009-10; this compares with one in 50 in North Dakota.
A longitudinal study in Texas published in 2011 found that 6 in 10 of the 1 million public school students it followed had been suspended or expelled at least once between the ages of 12 and 18.
To improve this figure the researchers suggest taking steps to create a positive school atmosphere, but also stress the need to support students with underlying mental health issues, drug problems or trauma.
QUIETNESS IN CLASSROOMS, 2003 v 2012
Comparing percentages of students who said there was 'never or hardly ever' noise and disorder in their classrooms.
Source: Pisa 2012 Results: What Makes Schools Successful? Resources, Policies and Practices:
Volume IV, Chapter 5, table IV.5.18. bit.lypisa2012_ch5_tables
2003 - 61.2%
2012 - 65.8%
2003 - 56.8%
2012 - 66.8%
2003 - 74.7%
2012 - 70.8%
2003 - 83.1%
2012 - 89.9%
2003 - 58.4%
2012 - 63.3%
2003 - 66%
2012 - 69.8%
Average for OECD
2012 - 67.4%.