Until recently, many teachers only got one word of feedback a year: “satisfactory.” And with no feedback, no coaching, there’s just no way to improve. Bill Gates suggests that even great teachers can get better with smart feedback — and lays out a program from his foundation to bring it to every classroom.

A passionate techie and a shrewd businessman, Bill Gates changed the world once, while leading Microsoft to dizzying success. Now he’s set to do it again with his own style of philanthropy and passion for innovation.