Data is the key to any successful school. According to John Hattie’s work, providing formative assessment ranks in the top three strategies for student achievement. If the staff is taught to collect, analyze and use data to change instruction, to provide differentiated learning for students, change will happen. This is one of the simplest, yet most difficult things to implement in a school. Teaching ourselves as educators to let go of any preconceived ideas we have about our own need to be successful as teachers, and letting the data tell the story, becomes a game changer for our students. It is a risky proposition for educators, but the pay off is so worth it. Once you see your chronic under-performing students smile at you because they understand and have confidence in their learning, you will be a believer. Here are two of our success stories.