Very soon, tens of millions of children around the world will start a new school year. It’s supposed to be the time for children to acquire the skills and knowledge they need to succeed in life. Are they getting that education in school? Not always. Nearly 25 percent of primary school-age children around the world can’t read, write or do basic mathematics. About one-quarter of these children have never had the chance to learn because they aren’t in school. Making sure that children learn – in other words, giving children the tools needed so they can reach their potential – is a global priority. Success requires understanding the most effective way to do this. That’s where evidence matters.