What is an Assessment Series percentile ranking and how should it be interpreted? 

This article is intended only for customers and partners using the Assessment Series.

A percentile ranking provides a measure of how a student performed on the assessment relative to other students who took the same assessment at the same grade level and is based on students’ scaled scores. If a student’s percentile ranking is listed as 80, it means that the student performed as well as or better than 80% of all CommonLit students who took that assessment at that grade level. Students with high percentile rankings can be said to have performed well relative to other students while students with low percentiles performed lower than other students. 

Please note that percentile rankings are only calculated after a sufficient number of students have taken the assessment and therefore might not be available right away when a student receives a score. They also may fluctuate slightly as more students take that assessment. 

In addition to providing insight into how a student performed on a specific assessment, percentile rankings can also be useful when looking at students’ growth. If a student grew significantly from the Pre-Assessment to the Post-Assessment, but their percentile ranking stayed the same, their growth was similar to that of other CommonLit students at that grade level.