Measuring Growth

This section of the online Help contains information about fundamental concepts in the TVAAS reporting. Having a basic understanding of these concepts will enhance your use of the data in the reports.

How TVAAS Measures Growth

Each year, the academic performance of students is evaluated using a variety of assessments. Districts, schools, and teachers receive results from these assessments, which provide important information about the achievement level of their students in tested grades and subjects or courses.

But because the achievement data is based on different groups of students each year, direct comparisons of data across years are often not meaningful or useful. For example, comparing the performance of last year's fifth graders to the performance of this year's fifth graders does not tell us how much academic growth either group of fifth graders made.

We offer a different set of measures. The growth of each group of students is measured as they move from one grade to the next or enter and complete a tested course. This approach yields growth measures that are fair, reliable, and useful to educators.

The process begins by generating measures of the average entering achievement level of the group of students served by each teacher, school, and district. Then a similar measure is generated for the group's average achievement level at the end of the subject and grade or course. To ensure that the measures are precise and reliable, TVAAS incorporates assessment data across years, grades, and subjects for each student.

The difference between these two achievement measures is calculated and then compared to a standard expectation of growth called expected growth. Effectiveness levels are then assigned to indicate how strong the evidence is that the group of students exceeded, met, or fell short of expected growth.

Simply put, the expectation is that regardless of their entering achievement levels, students should not lose ground academically, relative to their peers in the same grade and subject or course in the state. This standard is reasonable and attainable regardless of the entering achievement of the students served.

With this approach, it's possible for a group of students to demonstrate high growth, even if all of them remain in the same performance level from one year to the next. Each performance level includes a range of scores, so it's possible for a group's average achievement to rise or fall within a single state academic performance level.