Guilherme Lichand, na Folha:
Quem está certo, afinal? Resposta curta: não sabemos. Esse é o chamado “problema fundamental da inferência”: não observamos o mundo contrafactual em que tudo é igual, exceto a política que queremos avaliar.
A maneira mais segura e controlada de aprender a resposta seria “pilotando” a iniciativa: algumas escolas seriam sorteadas para serem reorganizadas (“grupo de tratamento”), enquanto outras não (“grupo de controle”). Em seguida acompanharíamos ao longo do tempo variáveis como frequência escolar, notas e evasão de todos os alunos, comparando aqueles cujas escolas foram reorganizadas com os demais.
Também monitoraríamos o tempo de deslocamento de casa até a escola, e as despesas da família com transporte.
[Atualização – 15/12] A Economist desta semana tem matéria e editorial sobre estudos randomizados controlados (RCT, randomised controlled trial).
Da matéria:
RCTs are being used more often to assess social policy in America, France and Scandinavia. In Britain there has been a flurry evaluating educational innovations—including one called “Teensleep”, in which the treatment group starts school at 10am (the idea is that they will learn more after a lie-in). Often the results are underwhelming, though no less important for that. A randomised experiment in New York showed that paying all teachers in a school more if their pupils do better in tests does not raise attainment.
But the emerging world remains far ahead. In Britain and America RCTs are mostly used to test minor policy tweaks, not fundamental reforms. In poorer countries, by contrast, they are being used to design welfare systems and measure corruption.
Do editorial:
To live in a modern democracy is to be experimented on by policymakers from cradle to grave. Education is intended to mould an upstanding future citizen; a prison sentence, to reshape someone who has gone astray. But without evidence, those setting policy for schools and prisons are little better than a doctor relying on leeches and bloodletting. Citizens, as much as patients, deserve to know that the treatments they endure do actually work.