Should schools reward well behaved kids with getting home early?

A secondary school in England is going to reward the behaviour of good pupils by allowing them to go home early, while naughty kids endure another 10 minutes of lessons? Teachers at Castle View school in Essex hope the move will lead to improved behaviour. So is this a good idea? Does rewarding good behaviour lead to children to learn by example or will 10 minutes really make that much of a difference? Stephen gets the views of former school principal Michelle Marken and commentator Emma Woolf.