Putting Assessment Data into Action: Scale Score vs. Percentile Rank — Five Student Scenarios

Summary:

In this article, you will learn:

• An increase in scale score indicates an increase in performance, but does not indicate whether a student is keeping up with their peers.
• An increase in percentile rank indicates a student is learning faster than their peers, but does not indicate if a student is meeting performance expectations.
• Decreases in scale score and/or percentile rank may be an indicator that a student needs more support, such as additional instruction, differentiation, or intervention.

How to Interpret Scale Scores and Percentile Ranks

Now that we’ve explored the differences between scale score and percentile rank, it’s time to explore several different score scenarios and what they might mean for instructional planning.

For this, we’ll examine five students in Mr. Russo’s fourth-grade class. Mr. Russo gives his students a diagnostic math assessment three times a year: at the beginning of the school year, at the middle of the school year, and again at the end of the school year. This helps Mr. Russo to understand where his students are starting, allows him to check in on their progress and make instructional adjustments if needed, and gives him an overall view of their growth across the school year.

Scale Score Increases, Percentile Rank Increases

At the beginning of the year, Kalid has a scale score of 1346 and a percentile rank of 55 on the math assessment. His scale score falls into the “meets expectations” performance category.

On the middle-of-year math assessment, Kalid has a scale score of 1409 and a percentile rank of 62. His scale score still falls into the “meets expectations” performance category.

This is great news for Kalid’s teacher. Not only have Kalid’s math skills improved (as shown by the increase in his scale score), but he’s gaining skills faster than his peers (as shown by the increase in his percentile rank).

This is a strong indication for Mr. Russo that Kalid is receiving the instruction and support he needs to succeed, and that Mr. Russo should continue providing Kalid with the same level of instruction and support for the remainder of the school year.

Scale Score Increases, Percentile Rank Stays the Same

At the beginning of the year, Julieta has a scale score of 1379 and a percentile rank of 61 on the math assessment. Her scale score falls into the “meets expectations” performance category.

On the middle-of-the-year assessment, Julieta has a scale score of 1401 and a percentile rank of 61. Her scale score still falls into the “meets expectations” performance category.

This is good news for Mr. Russo. Julieta’s scale score indicates that her math skills are improving. Having the same percentile rank in the fall and in the winter indicates that Julieta is learning at the same rate as her peers.

This indicates to Mr. Russo that Julieta is receiving the instruction and support she needs to grow her math skills. Mr. Russo decides to continue providing Julieta with the same level of instruction and support, but he makes a note to keep a close eye on her overall performance to make sure her growth doesn’t start to slow.

Scale Score Increases, Percentile Decreases

At the beginning of the year, Leo has a scale score of 1572 and a percentile rank of 86 on the math assessment. His scale score falls into the “exceeds expectations” performance category.

On the middle-of-year math assessment, Leo has a scale score of 1583 and a percentile rank of 81. His scale score still falls into the “exceeds expectations” performance category.

However, Mr. Russo is a little concerned. Although Leo is continuing to gain math skills (as shown by the increase in his scale score) and he still scores in the “exceeds expectations” category, the decrease in his percentile rank indicates that Leo is growing more slowly than his peers. If this trend continues, Leo’s growth might stagnate and he may even risk falling behind his peers in the future.

For Mr. Russo, this is a sign that he needs to review the instruction and support that Leo is receiving. Because Leo is currently exceeding grade-level expectations, it might be the case that he finds grade-level work “too easy” and “not engaging.”

In this case, ensuring Leo has opportunities to work with more complex, challenging material might be the best way to re-engage Leo and restart his growth. An adaptive personalized learning program might be the perfect fit for a student like Leo.

Scale Score Stays the Same

At the beginning of the year, Jennifer has a scale score of 1383 and a percentile rank of 62 on the math assessment. Her scale score falls into the “meets expectations” performance category.

On the middle-of-the-year assessment, Jennifer has the same scale score — 1383. Meanwhile, her percentile rank has dropped notably, down to 57. Her scale score still falls into the “meets expectations” performance category.

However, Mr. Russo is worried. Because Jennifer has the exact same scale score on both assessments, that indicates her math skills have not improved at all between the fall and the winter. Her decrease in percentile rank indicates that her peers are seeing greater skill gains.

Even though Jennifer currently “meets expectations,” if she continues to see no improvement or only very little improvement, she will fall behind her peers. It’s possible that she may even have “does not meet expectations” performance on the end-of-year assessment.

This is a strong signal that Mr. Russo needs to change the level of instruction and support that Jennifer is receiving. In this case, that might mean:

• Providing Jennifer with additional supports and scaffolds during Tier I instruction
• Providing Jennifer with adaptive personalized practice to give her additional instruction and intervention
• Providing Jennifer with Tier II intervention to give her additional targeted instruction and support in a small-group setting

Mr. Russo will need to rely on his professional expertise and knowledge of Jennifer to decide the best course of action for his student.

Scale Score Decreases

At the beginning of the year, Edward has a scale score of 1402 and a percentile rank of 63 on the math assessment. His scale score falls into the “meets expectations” performance category.

On the middle-of-year math assessment, Edward has a scale score of 1382 and a percentile rank of 57. His scale score still falls into the “meets expectations” performance category.

For Mr. Russo, this is an emergency. Not only has Edward not gained any additional math skills between fall and winter, he seems to have lost proficiency in skills he had previously mastered. Even though Edward is still in the “meets expectations” performance category, he will quickly fall behind his peers if his scale score continues to decline.

It’s possible that this decrease in scale score could be due to outside factors — maybe Edward had a headache or a stomach ache during the assessment and wasn’t able to concentrate on answering the items correctly.

However, after speaking with Edward and determining that Edward did the best that he could on the middle-of-year math assessment, Mr. Russo decides to provide Edward with Tier II intervention support to give him extra instruction and practice in a small-group setting. Even though Edward is currently “meeting expectations,” he is at significant risk of falling behind his peers if he does not receive additional support.

Scenarios with Students Who Do Not Meet Expectations

So far, we have looked at scenarios involving students who are meeting or exceeding grade-level expectations. What happens when those scenarios involve students who are not meeting grade-level expectations?

Scale Score Increases, Percentile Rank Increases

For a student who is not meeting grade-level expectations, an increase in both scale score and percentile rank is a strong sign that the student is learning at an accelerated rate.

If the student is receiving Tier II or Tier III intervention support, this may be an indication that the intervention is working. If the student continues to learn at an accelerated rate, they may be on the path to achieving grade-level goals.

Scale Score Increases, Percentile Rank Stays the Same

For a student who is not meeting grade-level expectations, an increase in scale score without a corresponding increase in percentile rank indicates that the student is learning at the same rate as their peers.

If the student needs to learn at an accelerated rate to achieve grade-level expectations, they may need more intensive support to achieve those goals. For example, if a student is already receiving Tier II intervention support, it may be appropriate to provide them with more intensive Tier III intervention support.

Scale Score Increases, Percentile Decreases

For a student who is not meeting grade-level expectations, an increase in scale score combined with a decrease in percentile rank may be an indication that the student is learning more slowly than their peers.

This student may need more intensive support to achieve grade-level expectations, such as a Tier II or Tier III intervention. If the student is already receiving Tier II intervention support, this may be an indication that they need Tier III intervention support. For students receiving Tier III intervention support, an intervention specialist may want to look for ways to increase the intensity of their intervention. For example, they may increase the length of the intervention sessions, increase the frequency of intervention sessions (e.g., the number of sessions per week), increase the focus on the discrete skills or subskills within the student’s identified areas for improvement, etc.

Scale Score Stays the Same

For a student who is not meeting grade-level expectations, a scale score that does not change between the beginning-of-year and the middle-of-year assessments would be a sign for concern.

This may indicate that the student is not receiving the level of instruction and support they need to grow. Tier II or Tier III intervention may be appropriate for the student. If the student is already receiving Tier II support, they may need to be moved to Tier III support. If the student is already in Tier III support, they may be a candidate for a special education evaluation.

Scale Score Decreases

For a student who is not meeting grade-level expectations, any decrease in scale score would be a cause for concern.

Similar to the above scenario, this decrease in scale score would indicate that the student is not receiving the level of instruction and support they need to grow. Tier II or Tier III intervention may be appropriate for the student. If the student is already receiving Tier II support, they may need to be moved to Tier III support. If the student is already in Tier III support, they may be a candidate for a special education evaluation.

The Power of Forecasts

Luckily, in addition to scale scores and percentile ranks, the adaptive math assessment that Mr. Russo uses provides a third data point: an end-of-year forecast for his state’s standardized assessment.

This forecast tells Mr. Russo what performance category the student is most likely to perform at on the end-of-year state assessment, as well as the probability (stated as a percentage) of that outcome.

Each school year, Mr. Russo gets two forecasts: one right away at the beginning of the year and an updated forecast at the middle of the year. The first forecast lets him see right away if a student is likely on track for success or if the student may benefit from additional instruction and support throughout the school year. The second forecast lets him see if his instructional plan is working or if he needs to make additional adjustments for the remainder of the school year.

For example, in the above image, Mr. Russo sees that Violet is 70% likely to perform at the Level 1 or “Standard Not Met” level on the end-of-year SBAC assessment. Because Mr. Russo’s goal is to have all students perform at Level 3 (Standard Met) or Level 4 (Standard Exceeded), this forecast helps him decide that Violet needs additional support to achieve her learning goals. In addition to giving her additional instruction and support during her daily Tier 1 instruction, Mr. Russo has her complete five sessions with an adaptive personalized learning program every week.

When Mr. Russo gets Violet’s updated forecast after she completes the middle-of-year assessment, Mr. Russo can see that her forecast has improved: instead of being 70% likely to perform at Level 1 on the SBAC, she’s now 45% likely to perform at Level 2 — and 22% likely to perform at Level 3! This is a strong indicator that Violet is receiving the instruction and support she needs to achieve accelerated learning and get on track for meeting grade-level expectations.

If her forecast had remained unchanged or worsened, that would have been an indicator that Mr. Russo needed to adjust instruction or provide more intensive support to help get her on track for success.

In both scenarios, Mr. Russo would have greater insight into Violet’s performance and the impact of his instruction on her learning.

More Than a Score

Of course, Mr. Russo doesn’t make instructional decisions based on assessments scores alone. He understands that a test score is a numerical representation of a student’s ability on a specific set of measures, but one number — or even a set of numbers — cannot represent an entire student.

When Mr. Russo is considering the needs and goals of his students, he also takes into account other factors such as:

• Does the student score similarly in all areas of the curriculum, or is there a specific area (such as math or reading) where their scores are particularly high or low?
• Has the student been screened for learning challenges such as dyslexia or dyscalculia?
• What kind of instructional support has the student been receiving? Would supplemental practice, adaptive personalized learning, or Tier II or Tier III support be appropriate for the student’s unique learning needs?
• How does the student’s performance and growth compare with the rest of the classroom — are there larger trends that may indicate Mr. Russo may want to adjust his Tier I instruction?
• How engaged is the student in his classroom? Has their level of engagement increased or decreased over the school year?

The data Mr. Russo gets from his assessments provide helpful information that allows him to get a more complete picture of each student in his classroom and their learning journeys. When combined with all the other information he knows about his students, Mr. Russo is better equipped to make the best instructional decisions for his class.

QUANTILE® and LEXILE® are registered trademarks of MetaMetrics, Inc. in the United States and abroad. Copyright © 2025 MetaMetrics, Inc. All rights reserved.