- Using PVAAS for a Purpose
- Key Concepts
- Concept of Growth
- Growth Measures and Standard Errors
- Growth Standard Methodology
- Predictive Methodology
- Topics in Value-Added Modeling
- Public Reports
- Additional Resources
- General Help
Misconception: If students are already high achieving, it is harder to show growth.
Educators serving high-achieving students are often concerned that their students' entering achievement level makes it more difficult for them to show growth. However, with PVAAS, educators are neither advantaged nor disadvantaged by the type of students that they serve. The modeling reflects the philosophy that all students deserve to make appropriate academic growth each year; as such, PVAAS provides reliable and valid measures of growth for students regardless of their achievement level.
PVAAS in Theory
The value-added models used in Pennsylvania are designed to estimate whether a group of students made enough progress to meet the growth standard, which is based on a comparison of the group's average achievement to their average prior achievement.
Furthermore, although Pennsylvania state assessments are designed to discriminate proficiency from non-proficiency, they are also designed to have sufficient stretch to discriminate between Below Basic, Basic, Proficient, and Advanced performance levels. Accordingly, there is sufficient stretch in the state testing scales to measure the growth of high-achieving students.
In fact, any test that is used in PVAAS analyses must meet three criteria, and state assessments meet these criteria:
- They demonstrate sufficient stretch so that both low-achieving and high-achieving students can show growth.
- They are aligned to state curriculum standards.
- The scales are reliable from year to year.
PVAAS is fair not only to LEAs/districts, schools, and teachers serving high-achieving students but it is also fair to the students themselves. The modeling that underlies PVAAS considers the growth of all students, regardless of their entering achievement, and the reporting shows whether the curriculum and instruction is targeted appropriately to these students. High-achieving students might require enrichment work in the same way that low-achieving students might need remediation to make sufficient growth.
PVAAS in Practice
Actual data might be the most readily apparent way to demonstrate that high-achieving students show similar growth as other achievement groups. The figure below plots the average achievement for the students served by an individual teacher in Pennsylvania against its growth index (the value-added estimate divided by its standard error) for PSSA Mathematics in grade 5 in 2019. Each dot represents one teacher. Regardless of the teacher's student achievement, there is little to no correlation to the growth index. In other words, the dots representing each teacher do not trend up or down as achievement increases; the cluster of dots is fairly even across the achievement spectrum. In the following graph, the actual correlation between the growth index and achievement is 0.15, which is weak. LEA/District and school value-added plots are similar to the teacher one shown below. This shows that high-achieving students can—and do—show growth through PVAAS, and that educators are neither advantaged nor disadvantaged by the achievement level of their students.
PENNSYLVANIA GROWTH INDEX VERSUS AVERAGE ACHIEVEMENT BY TEACHER
The next graph plots the percentage of tested students who are considered gifted for a specific teacher's roster in Pennsylvania against the teacher's growth index (the value-added estimate divided by its standard error) for PSSA Mathematics in grade 5 in 2019. Each dot represents one teacher. Regardless of the percentage of the teacher's students who are considered gifted, there is little to no correlation to the growth index. In other words, the dots representing each teacher do not trend up or down as the percentage of gifted students increases; the cluster of dots is fairly even across the entire range. In the following graph, the actual correlation between the growth index and the percentage of gifted students is 0.07, which is negligible. LEA/District and school value-added plots are similar to the teacher plot shown below. This shows that gifted students can—and do—show growth through PVAAS, and that educators are neither advantaged nor disadvantaged by the percentage of gifted students in their classes.
PENNSYLVANIA GROWTH INDEX VERSUS PERCENT GIFTED BY TEACHER