On the whole, schools deserve neither blame nor credit for their average achievement level, i.e., average TCAP scores. Achievement level is governed mostly by the percentage of disadvantaged students attending the school. Notice that schools with 70% or more disadvantaged students (marked in red when the ‘Economically Disadvantaged’ box is checked) are mostly to the left in this chart: This is because the education-related knowledge and skills of many disadvantaged students are months and years behind their peers when they enter school. In contrast, economically advantaged students tend to enter a school ahead of their peers. This difference is mostly a function of the communities served by the schools, not a reflection of school effectiveness.
Schools do deserve blame or credit for the average achievement growth of their students as measured by TVAAS scores. TVAAS measures how much students are learning each year, regardless of their starting point. It is a measure of school and teacher effectiveness. It measures what schools do with the students that are enrolled regardless of economic disadvantage or other differences. There are schools with high numbers of disadvantaged students that are very effective at lifting student achievement and others with high numbers of advantaged students that produce substandard levels of annual achievement growth.
Reading the Chart
The numbers along the left hand margin of the chart (y-axis) are TVAAS Academic Growth scores expressed as NCE scores. A score of 3, for example, would mean that the 3-year average achievement growth of students in this school is about 3 NCE units greater than the average achievement growth statewide in 2009 (the state's newly established baseline year). Attending schools with an NCE score of 3 for an entire K-12 career would result in a cumulatively greater level of academic achievement than would be expected from attendance at an average school.
What the Quadrants Mean
Schools in the upper left quadrant have mostly below-average achievers whose annual achievement growth is also being maximized. These are the schools that are successfully confronting some of the greatest challenges in teaching. They are likely to be using intensive, data-driven instruction and are producing high rates of academic growth.
Schools in the lower right quadrant also have above-average achievers, but their annual achievement growth is not being maximized. These schools are permitting their mostly advantaged students to coast through the curriculum with a middling effort. Their students are college-bound but may find themselves marginally prepared for high school and college-level studies.
Schools in the lower left quadrant have mostly below-average achievers whose annual growth is not being maximized. These schools are socially promoting substantial numbers of students. Many of their students fall further behind with each year of schooling and thus are more likely to drop out or be unprepared for college. These are the schools most in need of improvement. Their students are the most likely to need intensive instruction and catch-up rates of academic growth in the entering grades.