Understanding Student Growth

The Wyoming Accountability in Education Act (WAEA) requires the Wyoming Department of Education to produce reports of school quality, including measures of growth, achievement, equity, and college readiness. This page provides information on the growth indicator adopted by Wyoming which is based on Student Growth Percentiles (SGPs).

What is Growth? – video

 

Interpreting Growth Percentiles – video

 

Growth models have shown:

  • Growth is not correlated with how close a student is to proficient
  • Normative growth are gaps narrowing among student groups
  • Most low-achieving students not growing fast enough to catch up
  • Many proficient students are not keeping up
  • Many high-achieving schools show low growth and many low-achieving schools show high growth

Frequently Asked Questions

What are student growth percentiles?

A student growth percentile (SGP) describes a student’s growth compared to other students with similar prior test scores (their academic peers). Although the calculations for SGPs are complex, percentiles are a familiar method of measuring students in comparison to their peers. Growth is distinct from achievement; a student can achieve at a low level but grow quickly, and vice versa

We can measure student growth by calculating student growth percentiles that indicate the amount of growth a student made in a testing subject over the course of one year, relative to their academic peers. The student growth percentile allows us to fairly compare students who enter school at different levels. It also demonstrates a student’s growth and academic progress, even if she is not yet meeting standard.

A student growth percentile is a number between 1 and 99. If a student has an SGP of 85, we can say that she showed more growth than 85 percent of her academic peers. A student with a low score on a state assessment can show high growth and a student with a high score can demonstrate low growth. Similarly, two students with very different scale scores can have the same SGP.

Why measure growth?

Growth measures progress for students at all performance levels. A student can achieve at a low level but still improve relative to his academic peers; another student could achieve well but not improve much from year to year. Growth provides evidence of improvement even among those with low achievement and gives high achieving students and schools something to strive for beyond proficiency. Typical student growth percentiles are between about 36 and 64. Students or groups outside this range have higher or lower than typical growth. Differences of fewer than 10 SGP points are likely not educationally meaningful.

How are student growth percentiles calculated?

Student growth percentiles are measured by using a statistical method called quantile regression that describes the relationship between students’ previous scores and their current year’s scores.

To whom are students being compared? What is an “Academic Peer”?

For SGPs, a student is compared to his/her academic peers. A student’s “academic peers” are all students in Wyoming, in the same grade, and assessment subject that had statistically similar scores in previous years. In other words, they are students that have followed a similar assessment score path. A student’s growth percentile represents how much a student grew in comparison to these academic peers.

What is a median growth percentile?

The median growth percentile (MGP) is used in the Wyoming school rating system under the Wyoming Accountability in Education Act (WAEA), Enrolled Act 65. The median growth percentile summarizes student growth percentiles by district, school, grade level, or other group of interest. The median is calculated by ordering individual student growth percentiles from lowest to highest, and identifying the middle score, which is the median. The median may not be as familiar to people as the average, but it is similar in interpretation – it summarizes the group in a single number that is fairly calculated to reflect the group as a whole. (Medians are more appropriate to use than averages when summarizing a collection of percentile scores.)

What are adequate growth percentiles?

An adequate growth percentile (AGP) is a criterion referenced measure relative to proficiency. It measures how far away from proficiency a student is and answers: “how much growth would a student have to make to reach proficiency in three years or by the end of 8th grade. A student can make 70th percentile growth and still not meet AGP goals.

Can we still compare scores across years if the tests change?

Yes, because we are measuring normative growth, (i.e. students are being compared to their academic peers taking the same assessments), it is possible to calculate growth reliably. Student growth percentiles do not require identical tests or scales from year to year.

Can high scoring students still demonstrate growth?

Yes. Students that typically have high scores on state assessments will be compared to all other students in the state that also have high scores. The data show that even students that score at the top of the scale will have varied performance the next year, so the model allows us to identify growth for students at the upper end of the scale.

Which students get growth percentiles?

The students included in the student growth percentile calculations are those that attend Wyoming public school and took a state assessment. Certain test types and categories of students are excluded from this comparison group. Only students that have at least two years of consecutive scores are included. For example, if a student has a score in 5th grade, but not in 6th grade, she would not be included in the analysis. All available scores are used in the model, as long as they are consecutive. All students in the state that have valid and consecutive test scores in the same subject and grade form the norming population for the calculation of the SGPs. Each year that student growth percentiles are calculated, the norming population will consist of students enrolled and tested in that subject and grade during that school year. If students tested in the grades listed below, in addition to testing in at least one year prior, they will receive a growth percentile.

What can student growth percentiles tell us?

Student growth percentiles are primarily a descriptive model, telling us what amount of growth a student has made over the last year. This growth model is not a value-added model; it does not attempt to separate a teacher or school effect on student learning. SGPs can, however, help answer the following questions (Yen, 2007):

Parent Questions:

  • Is my child growing adequately toward meeting state standards?
  • Is my child growing more or less in Math than Reading, relative to other students in the state that scored similarly?

Teacher Questions:

  • Did my students grow adequately toward meeting state standards?
  • How much growth do my students need to become proficient?
  • Are there students with unusually low growth who need special attention?

Administrator Questions:

  • Are our students growing adequately toward meeting state standards?
  • How does the growth of students in my school compare to students in other schools?
  • Are students in different grade levels within my school growing similarly?

What kind of data will districts receive and when?

The following documents have been made available to districts:

  • Individual student reports, including student growth percentiles charts for math and reading
  • School-level reports that show individual students’ growth percentiles; one report for each subject/grade combination
  • District-level reports that show the median growth percentile of each school
  • School growth summary reports
  • Excel data files that include SGPs at the student-level and aggregate data at the school, district, and student group levels

Where can districts find the data?

Reports and excel files will be available to districts through the Wyoming Department of Education Fusion Portal.

How will the student growth percentile data be used?

With this information, teachers are able to:

  • determine whether students are making progress and in what content areas
  • differentiate instruction based on the progress of each student
  • create student growth trajectories to targets
  • identify and support at-risk students as well as those who need additional challenges

Principals are able to:

  • make evidence based decisions regarding the extent to which a teacher has met or exceeded the statistical expectation for a student’s achievement
  • better assign students to teachers
  • evaluate and support teachers in their improvement and professional growth
  • better understand which student groups, grades, and subjects are experiencing strong growth.

State policymakers are able to:

  • ascertain the effectiveness of particular districts and schools in meeting the needs of various groups of students
  • determine where growth is occurring even when aggregate achievement figures are below targeted levels

Where did student growth percentiles originate?

They were first developed in Colorado for use in their Accountability framework in 2007. Student growth percentiles have been adopted by 23 other states, and are under consideration in many more. Here’s a map of states using SGPs To view this PDF, click here to download Adobe Reader.

We have two primary ways of understanding how a child is performing on state assessments; they are Achievement/Proficiency and Growth.

Previously, we primarily looked at a student’s score and achievement level; these represent a snapshot of how the student was doing at that one point in time. We now have an additional way of understanding how our children are doing academically by looking at how much they’ve grown in the assessment subjects of reading and math. This new metric is called a Student Growth Percentile or SGP.

A student growth percentile describes a student’s growth over the past year compared to other students with similar prior test scores.

We are used to understanding a child’s growth in height or weight by comparing them to other children their age. If a student is taller than 45% of other children their age, we say that they are at the 45th percentile. With student growth percentiles, students are not only compared to other students in the same subject and grade, they are compared to students who have a similar score history on their state assessments. We refer to these students as their academic peers. Therefore, SGPs allow us to see how much students have grown over the course of a year, in comparison to their academic peers in the state of Wyoming.

An SGP is a number between 1 and 99. If your child has an SGP of 85, we can say that she showed more growth than 85 percent of her academic peers. Students with similar current test scores can have very different SGPs if they have different prior test scores. Students who have very low current test scores can have very high growth percentiles; conversely, students who have very high current test scores can have very low growth percentiles. It’s important to note that students must have two consecutive years of test scores in order to have an SGP, so reports for third graders and students new to Wyoming will not show the SGP.  Similarly, since PAWS is administered only in grades 3 – 8, the report for an 8th grader will not show a growth projection into the next year.

SGPs are meaningful because they tell a deeper story of a student’s progress over time – not simply where they are now. This means that, despite scoring below standard, students can show progress and be recognized for their achievement.

SGPs can provide valuable evidence to help understand if students are making an adequate amount of academic growth from one year to the next. They are an additional tool that can help parents engage with teachers and administrators in constructive conversations about their child’s learning. Questions that a parent might want to ask are:

  • What steps can we take since my child’s growth in reading was low and s/he needs to catch up?
  • Is my child on track to reach proficiency in math?
  • Did my child make good progress last year, or is s/he losing ground?

We have a number of measures we rely on to understand our children’s academic progress. SGPs should be viewed in conjunction with other information about how they are progressing in school, such as their grades, completion of class assignments, and scores on teacher-developed tests. All of these indicators of student performance together form a more complete picture of student success in school.