The idea behind standardized tests in education is to see if the student population has achieved a particular standard that must be met by all. In NY State, education is moving toward Core Curriculum Standards and those must be taught in all grades across the board. At grades 6 and 9 and 12, although a particular standard must be addressed let's say in science, it becomes more rigorous as the student's grade level progresses. Periodic assessments must be done to see what level the student is achieving and to re-teach anything that hasn't be successfully taught. This is called data analysis, another important idea that is being used currently in education. It is not simply enough to give an exam. Teachers are supposed to analyze which questions weren't successfully learned by students and re-teach those concepts using a wide variety of methods. Eventually, the hope is that whether you go to school in a city, rural community or suburb, students will learn the same curriculum and this will be demonstrated by the results of standardized testing.