Dr. William Sanders first developed this model in Tennessee to examine longitudinal sustained academic growth of each child based of assessment data. This model was intended to make effective use of data that was collected from criterion and norm-referenced assessments.
Since 1992, it tracked Tennessee’s students scores in every subject, every grade, and with every teacher.
It’s the largest data base ever assembled.
It’s mandatory in Pennsylvania and Ohio as well as in over 300 districts and across the U.S. HISD uses the EVAAS which is a Value-Added system that was also created by Dr. Sanders to measure student growth and teacher effectiveness.
The Value-Added approach attempts to level the playing field by focusing on the growth of each student rather than achievement.
Using a statistical analysis of several test scores, it tracks the growth of an individual student's improvement from year to year, and uses that progress to estimate the effectiveness of teachers, principals and schools.
These are most traumatic to student learning in schools because these patterns happen when the lowest achievers make the greatest gains in the classroom. This means the high-achieving students are held back.
This is the case where the teacher focuses instruction on the high achievers and the other students receive less attention. These patterns are also particularly dangerous because the slower and middle students will not show much growth.
These patterns arise when the teacher focuses their instruction on the average students in the class. Therefore, the average students make the greatest gains and those that at the bottom and top show less gain.
As one travels up the grade levels, the variability of teacher effectiveness increases.
The difference in student achievement could be a function of the teacher sequence that a child went through.
* For example, a study showed that 5 th grade math students who were assigned to top teachers for 3 consecutive years scored at the 96 th percentile. On the contrary, students assigned to a series of ineffective teachers for 3 consecutive years scored in the 44 th percentile.
Dr. Sanders research in Tennessee also indicated that 5 th grade students who had a series of three highly effective teachers in a row, gained 50 percentile points more on the state’s assessment than other students who had three ineffective teachers.
A similar study conducted in Dallas also showed identical results.
The use of Value-Added data enables schools to see whether or not students are making the gains that they should. It allows each teacher to be more confident with working with the students that they receive because their effectiveness will be measured based on the gains that each student makes. Additionally, the success of a student or the teacher is not limited to the passing of one particular assessment. The use of differentiated instruction in the classroom will ensure that all students make gains across the board. Ultimately, the use of the Value-Added Model paints a better picture of how each student is performing each school year.