Ms MacKay urged schools to use "challenging" material. Some of the best work in classrooms was prompted by texts which have "enough mystery in them to make pupils want to grapple with them".
Different ways of learning and teaching were also important. This included giving pupils scope to ask the questions, not just the teachers.
Ms MacKay quoted a "powerful message" from one boy in a class which had adopted this approach who told inspectors: "When the teacher asks the questions, I already know the answers. This way, I get to ask the questions I don't know the answers to."