Those are the things I want to highlight.

This is more about a different way of trying to measure progress than trying to favor any group of students or schools.

We were looking for something that was valid and reliable . . . for something that would measure teacher effectiveness that was neutral. This measures student improvement and the value that teachers bring to student...

Every state gets to choose their tests and to define the achievement levels required. And so states vary widely in their expectations of what students should know.