A student growth percentile (SGP) is a measure of a student’s relative academic progress, compared to students with similar prior test scores. It is an extremely valuable assessment tool, allowing educators to identify which students are making academic progress, and which are not.

SGPs are calculated using a norming population, or “standard group,” of students with valid and consecutive tests from a particular year and grade. The norming group for Washington’s SGP model includes all students in the state who have a valid test score in a particular subject and grade, and at least one previous test score.

The SGP package is designed to be used with the open source R software environment. R is available for Windows, OSX, and Linux and can be compiled to run on just about any system. Because SGP analyses are conducted within the R programming language, familiarity with this platform is essential. Those who are not familiar with R should spend some time becoming familiar with the basic tools of this software before attempting to run SGP analyses.

There are many ways to conduct SGP analyses with different variations in data format and function use. For example, the lower level functions studentGrowthPercentiles and studentGrowthProjections can be accessed with either WIDE or LONG format data. Higher level wrapper functions, such as prepareSGP and updateSGP, often utilize the LONG format, providing several preparation and storage benefits over the WIDE formats. For operational SGP analyses, it is typically more efficient to use these higher level wrapper functions.

While SGPs are very useful tools, they must be interpreted carefully and in context. It is important to understand the limits of this methodology and to incorporate other assessment models into a classroom curriculum. In addition, teachers should be aware of the limitations of this tool, including its potential for overstatement and bias.

This article will examine the underlying assumptions and methodologies of SGPs, as well as some common issues that arise in their interpretation. We will also discuss some of the most effective strategies for using SGPs in a teaching and learning environment.

SGPs are a powerful and useful assessment tool for measuring student achievement and growth, especially when they are combined with other assessment methods. However, the calculations and interpretation techniques are complex. In this article, we will review the process of calculating and interpreting SGPs and provide some recommendations for best practices.

SGPs are a key tool for assessing student growth and understanding the effectiveness of a curriculum. In addition, they can help to inform instruction and improve student outcomes. This article will review the underlying assumptions and methodologies of student growth percentiles, as well as some of the most common issues that arise in their interpretation. In addition, we will provide some suggestions for improving the accuracy and effectiveness of SGPs.