Teacher Value-Added

Understanding the Report

Growth Index

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

District Average

The option to display District Average is available when there is sufficient data. The District Average appears as a vertical purple line. This value represents the average of all teacher index values in the district for the selected grade and subject or course.

Growth Indicators

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

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

Color	Growth Index Compared to Expected Growth	Interpretation
Exceeds Expected Growth	At least 2 standard errors above	Significant evidence that students made more growth than expected (the index is 2 or greater).
Meets Expected Growth	Between 1 standard error above and 1 standard error below	Evidence that students made growth as expected (the index is between -2 and 2)
Does Not Meet Expected Growth	More than 2 standard errors below	Significant evidence that students made less growth than expected (the teacher's index is less than -2).

When a growth index falls exactly on the boundary between two colors, the higher growth indicator is assigned.

Growth Measure

Each growth measure is a conservative estimate of the academic growth the students made, on average, in a grade and subject or course. The 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 gain model than it is for other assessments.

Standard Error

All growth measures on the EVAAS 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 expected growth.

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

Expected Growth

Expected Growth represents the point at which the students' scores, on average, align with expectations.

Expected Growth signifies the minimum amount of academic growth that educators should expect a group of students to make in a subject and grade or course. In general, this signifies appropriate, expected academic growth. Simply put, the expectation is that regardless of their entering achievement level, students served by each 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. Expected Growth is represented by a vertical green line in the graph.

Distribution of Teachers

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

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

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 state
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 course 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.