Proficiency Rates vs. Student Growth: What Is the Difference?

Proficiency rates and student growth are two common ways to describe student performance, but they answer different questions. A proficiency rate is a status measure: it shows how many students met a performance standard at a single point in time. Student growth is a change measure: it shows how performance moved over a period of time. The two cannot be used interchangeably, and a school can look strong on one while looking weak on the other.

This article explains the difference in plain language, with an illustrative example and a guide to reading New York results. It draws on general assessment-literacy material from the Michigan Assessment Consortium and the American Institutes for Research (AIR). Source-check date: October 12, 2026.

What each measure answers

Proficiency answers a status question: How many students met the standard? Growth answers a change question: How much did performance change? The Michigan Assessment Consortium describes proficiency as a status measure and growth as an attempt to communicate change in student performance over time. The two require different interpretations.

Proficiency: a snapshot against a standard

Proficiency is often called a status measure because it represents performance at one point in time. The Michigan Assessment Consortium’s May 2017 brief explains that student test scores are placed into performance categories based on cut scores. For example, one state system described by the consortium uses four categories: Not Proficient, Partially Proficient, Proficient, and Advanced. The number of categories and the cut scores are policy decisions, not natural facts.

A proficiency rate usually reports the percentage of tested students who reached the proficient level or above. That makes it easy to communicate: a parent can see whether a school’s students are meeting the state’s standard in a given subject and grade. But the rate is a snapshot. It does not show whether the same students improved, stalled, or declined from the prior year.

Growth: change over time

Growth attempts to communicate the change in student performance over some period of time. Instead of asking how many students met the standard, growth asks how much performance changed. Growth can be reported as a simple gain score, a growth percentile that compares a student’s change with that of academic peers, or a value-added estimate that uses statistical controls. The exact method matters, because different growth models can produce different results for the same school.

The AIR brief “Proficiency or Growth?” explores how educators can write student learning targets using either a proficiency approach or a growth approach. Proficiency targets focus on reaching a standard; growth targets focus on change. The brief examines benefits and drawbacks of each, which is a useful reminder that the choice is not just technical. It reflects what a school or state wants to prioritize.

How growth is calculated, in concept

Most growth measures need at least two data points for the same student, usually test scores from consecutive years in the same subject. The student’s later score is compared with the earlier score. Some models then compare that change with the typical change of students who had similar prior scores. This is why growth calculations often require linked student data and may exclude students who are new to the district, missed a test, or lack a prior score. The denominator for a growth measure is therefore not always the same as the denominator for a proficiency rate.

New York State’s assessment and accountability rules are set by the New York State Education Department (NYSED). This article does not verify the current NYSED growth formula, the current performance levels, or the weight given to growth in accountability. Those details can change and should be checked on current NYSED report cards and official accountability documents.

An illustrative example

The following example is invented to show the difference. It does not describe a real student, school, or district.

Suppose a student scores 230 on a grade 4 mathematics test and 240 on a grade 5 mathematics test. If the grade 5 proficiency cut score is 245, the student is not proficient in grade 5. But the student’s score increased by 10 points, so a growth measure would record positive change. Now suppose another student scores 260 in grade 4 and 255 in grade 5. If the grade 5 cut score is 245, that student remains proficient. But the score declined by 5 points, so a growth measure would record negative change.

The example shows why a proficiency rate and a growth measure can point in different directions. The first student is below proficiency but growing. The second is proficient but losing ground. A school that only reports proficiency would miss the first student’s progress; a school that only reports growth would miss the second student’s continued access to advanced work.

Comparison table

What the numbers can and cannot tell you

Proficiency rates are useful for answering whether students are meeting a defined standard. They are less useful for answering whether a school is helping students improve, especially if the school serves students who start far below or far above the standard. A high proficiency rate can reflect strong instruction, but it can also reflect a student body that entered with high scores. A low proficiency rate can reflect weak instruction, but it can also reflect a student body that entered with low scores or a high number of students still learning English.

Growth measures are useful for answering whether performance is changing. They can highlight progress by students who are not yet proficient, and they can show whether students who are already proficient are continuing to advance. But growth is not a simple, model-free fact. It depends on the test’s scale, the prior score, the comparison group, and the statistical method. Growth measures can also be less reliable for small groups, and they may exclude students without linked scores.

Neither measure, by itself, proves that a school caused a particular result. Proficiency and growth are indicators. They can raise questions, but they do not answer every question about curriculum, teaching, resources, or student needs.

Why the distinction matters for families

A school with high proficiency but low growth may be serving many students who already meet the standard, while average score changes are flat. A school with low proficiency but high growth may be helping students catch up, even though many students are still below the standard. Neither pattern is automatically good or bad. The pattern tells you what question to ask next.

Many state accountability systems include both status and growth indicators to provide a fuller picture. When both are reported, they should be read together: Are students meeting the standard? Are they improving? Are the same groups of students improving, or are gaps widening?

Common misconceptions

Reading New York results without mixing them up

In New York, families will encounter assessment results in state and district reporting. When you see a number, first ask what kind of number it is:

• Proficiency rate: a percentage of students meeting a standard. Check the subject, grade, test year, and performance level used.
• Growth measure: a change statistic. Check the model, the years compared, and which students had linked scores.

Then check the denominator. A proficiency rate usually counts students who took the test. A growth measure may count only students with scores in both years. If the two numbers use different groups of students, they are not directly comparable.

Because New York’s accountability system and reporting rules are set by NYSED and can be updated, the safest next step is to read the current NYSED school report card and the state’s current accountability documentation. This article explains the stable concept, not the current formula.

Questions for parents

• Is this number a proficiency rate or a growth measure?
• Which subject, grade, and school year does it describe?
• Who is included in the denominator? All students, tested students, or only students with linked scores?
• How does the school explain growth for students who are already proficient?
• How does the school explain growth for students who are far below proficiency?
• Are results available for student groups, such as students with disabilities, English language learners, and economically disadvantaged students?
• What is the margin of error or confidence interval, especially for small groups?
• What does the school plan to do differently based on this information?

Sources and methodology

This article is a general explainer. It defines proficiency and growth using the Michigan Assessment Consortium’s May 2017 brief “Proficiency and Growth: What’s the difference?” and the American Institutes for Research’s April 2015 brief “Proficiency or Growth? An Exploration of Two Approaches for Writing Student Learning Targets.” Those sources support the core distinction: proficiency is a status measure at a point in time, while growth describes change over time. The illustrative example is invented for clarity and is not drawn from any real student or school record.

New York-specific policy details are not verified in this article. The source-check date is October 12, 2026. For current New York assessment performance levels, growth calculations, and accountability rules, consult the New York State Education Department’s current official report cards and accountability documents.