Table of Contents

Teacher Value-Added

Understanding the Report

Growth Index

The growth index is a reliable measure of whether students exceeded, met, or fell short of the growth standard. This value takes into account the amount of growth the students made as well as the amount of evidence above or below the growth standard. Specifically, the growth index is the growth measure divided by its standard error.

The growth index is plotted as a color-coded diamond in the growth index graph at the top of the report.

Growth Color Indicators

Each growth index is color-coded to indicate how strong the evidence is that the teacher's students exceeded, met, or fell short of the growth standard.

The key at the bottom of the report provides guidance for interpreting the colors.

Growth Color IndicatorGrowth Index Compared to the Growth StandardInterpretation
Well Above

At least 2 standard errors above

Significant evidence that the teacher's group of students exceeded the growth standard

Above

Between 1 and 2 standard errors above

Moderate evidence that the teacher's group of students exceeded the growth standard
Meets

Between 1 standard error above and 1 standard error below

Evidence that the teacher's group of students met the growth standard
Below

Between 1 and 2 standard errors below

Moderate evidence that the teacher's group of students did not meet the growth standard
Well Below

More than 2 standard errors below

Significant evidence that the teacher's group of students did not meet the growth standard
When a growth index falls exactly on the boundary between two colors, the higher growth color indicator is assigned.

Growth Measure

Each growth measure is a conservative estimate of the academic growth a teacher's students made, on average, in a grade and subject or Keystone content area. A teacher's growth measure is based on students that were linked to the teacher and the percentage of instruction. Because the growth measures are estimates, consider their associated standard errors as you interpret the values.

The growth measure is calculated differently for assessments analyzed with the growth standard methodology than it is for PSSA Science and Keystone assessments.

See also: Measuring Growth.

Standard Error

All growth measures on the PVAAS reports are estimates. All estimates have some amount of measurement error, which is known as the standard error. This value defines a confidence band around the growth measure, which describes how strong the evidence is that the group of students exceeded, met, or fell short of the growth standard.

For more information about standard errors, see Growth Measures and Standard Errors.

Growth Standard

The growth standard represents the point at which the teachers' students' scores, on average, align with expectations.

The growth standard signifies the minimum amount of academic growth that educators should expect a group of students to make in a subject and grade or Keystone content area. In general, this signifies appropriate, expected academic growth. Simply put, the expectation is that regardless of their entering achievement level, students served by each LEA/district, school, or teacher should at least make enough progress to maintain their achievement level relative to their peers. This is a reasonable target for educators who serve all types of students. The growth standard is represented by a vertical green line in the graph.

There are no individual student measures of growth in PVAAS. This is because there are so fewer data points for an individual student and the error around that measure would be larger, making it difficult to know if a student made growth or not. However, growth measures based on groups of students include much more data, so the impact of measurement error associated with each individual test score is minimized. PVAAS uses many years, grades, and subjects in the analyses. Because so much data is included, the academic growth of the group can be measured with much greater precision and reliability than the growth of a single student. In PVAAS Value-Added reports, a group of 11 students is needed to calculate a measure of growth. In PVAAS Diagnostic reports, a group of five students in any achievement category is needed to calculate a growth measure.

Distribution of Teachers

This distribution lists the number of teachers in each growth color indicator in the selected grade and subject or course in the reference group. This enables each teacher to compare their teacher value-added results with other teachers in the reference group for the same state-assessed grade and subject or Keystone content area.

It's important to understand that PVAAS does not fit teachers into a predetermined distribution. The number of teachers who appear in each growth color indicator is determined by the amount of statistical evidence that each teacher's group of students exceeded, met, or fell short of the growth standard. The methodology does not predetermine the number or percentage of teachers whose values fall into each growth color indicator range. In fact, the relative size of each growth color indicator group varies by grade and subject or Keystone content area, depending on the evidence of measurable differences in growth.

The use of Normal Curve Equivalents (NCEs) for assessments analyzed with the growth standard methodology should not be confused with the question of whether PVAAS fits LEAs/districts, schools, or teachers into a specific distribution. PVAAS converts scale scores for these assessments into state NCEs before analyzing the data. This conversion provides a common, equal-interval scale for measuring the growth of groups of students, but it does not predetermine the distribution of LEAs/districts, schools, or teachers.

Student List

To see the list of students linked to the teacher in the data, click the Student List button above the chart.

The Used in the Analysis column indicates whether each student was used in the analysis that generated the teacher's value-added report. The most common reasons that students are excluded from the analysis are:

  • They don't have assessment scores
  • They aren't linked to a teacher
  • They don't meet membership or attendance rules
  • Their scores are outliers
  • They are new to the reference group
  • They don't have enough prior assessment data

Some of these exclusion rules might not apply to all subjects. Statistical Models and Business Rules describes various conditions that can cause a student to be excluded from the analysis.

Teachers who have a Teacher Value-Added report in the selected subject, grade, or Keystone content area in the most recent year have access to this report.

Showing the Growth Index or Growth Measure

The report displays the growth index graph by default. You can choose the growth measure graph from the menu below the graph. For more information about the growth measure graph, see Interpreting the Data.

More Information

Self-Reflection Guide for PVAAS Teacher Reporting

PVAAS Virtual Shelf