The Welsh government is to hold a public inquiry into test drilling for gas in the Vale of Glamorgan.

BBC: Public inquiry over gas drilling in Vale of Glamorgan

The inquiry began after a teaching assistant detected problems in a take-home test.

BBC: Harvard University file picture

The inquiry follows an earlier review of 13 schools in which five failed to pass the charity test.

BBC: Private schools face investigation into charity status

The right blend of qualitative and quantitative inquiry can illuminate the scope and dimensions of a problem, uncover root causes, and reliably test whether alternative solutions actually work to produce lasting change in the real world.

FORBES: Where There's Smoke, There's Fire: A Call to Action for Better Indoor Air Pollution Research

Speaking to the BBC on Monday, Mr Miliband warned the prime minister that "this is the moment when our promises are being tested, " adding the big test was whether victims of phone hacking - the illegal press practice that sparked the Leveson Inquiry - would be happy with what the government proposed.

BBC: Lord Justice Leveson

The committee's report said it was "regrettable" that ETS, the American company behind the doomed test delivery, withdrew from the UK and "chose not to engage" with Lord Sutherland's inquiry into the fiasco.

BBC: Ministers 'too involved' in Sats