Pembrokeshire student struggles in 'intense' South Korea
Three Welsh teenagers swapped school life in Pembrokeshire for lessons in South Korea to find out why the country's students perform so well in Pisa tests.
The tests involve 15-year-olds in more than 70 different countries sitting the same exams in maths, science and reading, every three years.
One obvious difference between the education systems is the long hours South Korean pupils put in, with hours of self-study and private night school classes after lessons end.
Sarah, 16, struggled to stay awake at her desk and said it was “a really intense day”.
School Swap: Korea Style can be seen on BBC World News at varying times over the weekend January 6 and 7, 2018.
This programme was first transmitted on BBC World News in March 2017.
28 Nov 2016