There are also huge differences between primary and secondary/tertiary education systems.
Primaries naturally lend themselves to individual class bubbles as there's often very little mixing outside those (siblings aside) and schools with multi-form years can still be segregated reasonably well with a bit of planning.
Secondary/tertiary all that goes to pot. You get children mixing with the whole year due to subject choice differences, streaming, etc plus a lot more movement around the school premises. Hence the 200 pupil bubbles. That's why the secondary/tertiary model moved to testing (and specifically lateral flow testing). However many people realised that reporting a positive test meant a pain in the arse for the whole family so they simply didn't bother (especially if asymptomatic). Testing taking place at school is less error prone but far more expensive and time consuming from a schools point of view.
There are also huge differences between primary and secondary/tertiary education systems.
Primaries naturally lend themselves to individual class bubbles as there's often very little mixing outside those (siblings aside) and schools with multi-form years can still be segregated reasonably well with a bit of planning.
Secondary/tertiary all that goes to pot. You get children mixing with the whole year due to subject choice differences, streaming, etc plus a lot more movement around the school premises. Hence the 200 pupil bubbles. That's why the secondary/tertiary model moved to testing (and specifically lateral flow testing). However many people realised that reporting a positive test meant a pain in the arse for the whole family so they simply didn't bother (especially if asymptomatic). Testing taking place at school is less error prone but far more expensive and time consuming from a schools point of view.