Growth Model vs. Proficiency Model and Why This Matters

What Educators Can Learn from Each Model

Ladder against library bookshelf
Measuring student growth or proficiency can be compared to the rungs of a ladder- How many rungs did the student climb?. EyeEm/ Getty Images

More and more attention is being paid to an essential question that educators have debated for years: How should education systems measure student performance? Some believe that these systems should focus on measuring student academic proficiency, while others believe they should emphasize academic growth

From the  Offices of the US Department of Education to the conference rooms of local school boards, the debate concerning these two models of measurement is offering new ways to look at academic performance.

 

One way to illustrate the concepts of this debate is to imagine two ladders with five rungs each side by side. These ladders represent the amount of academic growth a student has made over the course of a school year. Each rung marks a range of scores - scores that can be translated into ratings from below remedial to exceeding goal.

Imagine that the fourth rung on each ladder has a label that reads "proficiency" and there is a student on each ladder. On the first ladder, Student A is pictured on the fourth rung. On the second ladder, Student B is also pictured on the fourth rung. This means that at the end of the school year, both students have a score that rates them as proficient, but how do we know which student has demonstrated academic growth? 

To get to the answer, a quick review of middle and high school grading systems is in order.

Standard Based Grading vs. Traditional Grading

The introduction of the Common Core State Standards (CCSS) in 2009 for English Language Arts (ELA) and Math influenced different models of measuring student academic achievement in grads K-12.

The CCSS were designed in order to offer "clear and consistent learning goals to help prepare students for college, career, and life." According to the CCSS:

  "The standards clearly demonstrate what students are expected to learn at each grade level, so that every parent and teacher can understand and support their learning."

Measuring student academic performance by standard such as the ones outlined in the CCSS is different than more traditional grading methods that are used in most middle and high schools.

The traditional grading methods have been around for over a century, and the methods include:

  • One grade/entry given per assessment
  •  Assessments based on a percentage system
  • Assessments measure a mixture of skills
  • Assessments may factor in behavior (late penalties, incomplete work)
  • Final grade is an average of all assessments

Traditional grading is easily converted to credits or   Carnegie Units, and whether results are recorded as points or letter grade, traditional grading is easy to see on a bell curve. 

Standards-based grading, however, is skill based, and teachers report on how well students demonstrate understanding of content or a specific skill using specific criteria aligned to a scale: 

"In the United States, most standards-based approaches to educating students use state learning standards to determine academic expectations and define proficiency in a given course, subject area, or grade level."

(Glossary of Education Reform):

In standards-based grading, teachers use scales and systems that may replace letter grades with brief descriptive statements: does not meetpartially meetsmeets the standard, and exceeds the standard OR remedial, approaching proficiency, proficiency, and goal.

 In placing student performance on a scale, teachers report on: 

  • Learning goals and performance standards based on a pre-determined rubric
  • One entry per learning goal
  • Achievement only with no penalties or extra credit given

Many elementary schools have embraced standards-based grading, but there is increasing interest in having standards-based grading at the middle and high school levels. Reaching a level of proficiency in a given course or academic subject could be a requirement before a student earns course credit or is promoted for graduation. 

Proficiency Model vs. Growth Model

A proficiency-based model uses standards-based grading in order to report on how well students have met a standard. If a student fails to meet an expected learning standard, a teacher will know to target additional instruction or practice time.

In this way, a proficiency-based model is geared for differentiated instruction for each student.

A report commissioned by the American Institutes for Research in April 2015 by Lisa Lachlan-Haché and Marina Castro titled Proficiency or Growth? An Exploration of Two Approaches for Writing Student Learning Targets explains some of the benefits for educators in using a proficiency model:

  • Proficiency targets encourage teachers to think about a minimum expectation for student performance.
  • Proficiency targets do not require pre-assessments or any other baseline data.
  • Proficiency targets reflect a focus on narrowing achievement gaps.
  • Proficiency targets are likely more familiar to teachers.
  • Proficiency targets, in many cases, simplify the scoring process when student learning measures are incorporated into evaluation. 

In the proficiency model, an example of a proficiency target is "All students will score at least 75 or the standard of proficiency on the end-of-course assessment." The report also listed several drawbacks to proficiency-based learning including:

  • Proficiency targets may neglect the highest and lowest performing students. 
  • Expecting all students to achieve proficiency within one academic year may not be developmentally appropriate.
  • Proficiency targets may not meet national and state policy requirements.
  •  Proficiency targets may not accurately reflect teachers’ impact on student learning. 

It is the last statement about proficiency learning that has caused the most controversy for national, state, and local school boards. The have been objections raised by teachers across the country based on concerns about the validity of using proficiency targets as indicators of individual teacher performance.

A quick return to the illustration of the two students on two ladders, both on the rung of proficiency, can be seen as an example of the proficiency-based model. The illustration provides a snapshot of student achievement using standards-based grading, and captures each students' status, or the academic performance of each student, at a single point in time.

But the information about a student's status still does not answer the question "Which student has demonstrated academic growth?" Status is not growth, and to determine how much academic progress a student has made, a growth model approach may be needed.

In a report titled A Practitioner’s Guide to Growth Models by Katherine E. Castellano, (University of California at Berkeley) and Andrew D. Ho (Harvard Graduate School of Education), a growth model is defined as:

"A collection of definitions, calculations, or rules that summarizes student performance over two or more time points and supports interpretations about students, their classrooms, their educators, or their schools."

The two or more time points mentioned in the definition could be marked as the use of pre-assessments at the beginning of lessons, units, or end of year coursework and the post-assessments given at the end of lessons, units, or end of year course work.

In describing the benefits of using a growth model approach, Lachlan-Haché and Castro explained how a pre-assessment can help teachers to develop growth targets for the school year. They noted:

  • Growth targets recognize that teachers’ impact on student learning may look different from student to student. 
  • Growth targets recognize teachers’ efforts with all students.
  • Growth targets can guide critical discussions around closing achievement gaps. 

An example for a growth model target or goal is "All students will increase their pre-assessment scores by 20 points on the post-assessment." This kind of target or goal may address individual students rather than a class as a whole.

Just like proficiency-based learning, the growth model has several drawbacks. Lachlan-Haché and Castro listed several that again raise concerns about how a growth model might be used in teacher evaluations:

  • Setting rigorous yet realistic growth targets can be challenging.
  •  Poor pretest and posttest designs can undermine the value of growth targets.
  •  Growth targets may present additional challenges for ensuring comparability across teachers.
  •  If growth targets are not rigorous and long-term planning does not occur, the lowest performing students may not achieve proficiency. 
  • Growth target scoring is often more complex.
  • If growth targets are not rigorous and long-term planning does not occur, the lowest performing students may not achieve proficiency. 

The measurements from a growth model may help teachers better identify the needs of students at the extreme ends of an academic spectrum, both high and low. Moreover, the growth model offers an opportunity to increase academic growth for higher achieving students. This opportunity may be overlooked if teachers are limited to the proficiency model. 

So which student has demonstrated academic growth?

A final visit to the illustration of the two students on the ladders could yield a different interpretation if the model of measurement is based on the growth model. If the status of each student of the ladder at the end of the school year is proficient, academic progress could be tracked using data on where each student began at the start of the school year. If there was pre-assessment data that showed that Student A began the year as already proficient, and already on the fourth rung, then Student A had no academic growth over the school year. Moreover, if Student A's proficiency rating was already at a cut-score for proficiency, then Student A's academic performance with little growth might dip in the future, perhaps to the third rung or approaching proficiency.

In comparison, if there was pre-assessment data that showed Student B began the school year at the second rung, at a remedial rating, then the growth model would demonstrate that there was substantial academic growth. The growth model would show that Student B climbed two rungs in reaching proficiency. 

Conclusion

Ultimately, both the proficiency model and the growth model have value in developing education policy for use in the classroom. Targeting and measuring students on their levels of proficiency in content knowledge and skills is helpful is preparing them to enter college or to enter the workforce. There is value in having all students meet a common level of proficiency. However, if the proficiency model is the only one used, then teachers may not recognize the needs of their highest performing students in making academic growth. Similarly, teachers may not be recognized for the extraordinary growth their lowest performing student may make.

In the debate between a proficiency model and a growth model, the best solution is finding the balance in using both to measure student performance.