Improving teacher effectiveness

Guilford County, North Carolina schools don't need to guess what effective teaching looks like. After using SAS® EVAAS® for K-12 for more than a decade, the school system has a longitudinal, data-driven means to measure teacher effectiveness that has propelled significant increases in the percent of students passing state-mandated tests.

Rather than offer bonuses to any teacher to work in lower socioeconomic schools, Guilford first identifies high-performing teachers and then recruits them to these "Mission Possible" schools where they can earn bonuses of up to $12,000 a year for increasing student performance above district averages.

"We use EVAAS to attract effective teachers and continue measuring their effectiveness," explains Amy Holcombe, Executive Director of Talent Development for the 72,000-student school system. When a teacher applies for a job within the county, the effectiveness score is checked. Teachers applying from other districts in the state are asked to provide their scores if they are available.

Passing rates near 100 percent in program schools

Guilford County is located in central North Carolina and includes the city of Greensboro. The school system has 72,000 students, and more than half qualify for free or reduced lunch through the National School Lunch Program.

"Ten years ago we didn't have a lot of indicators of teacher effectiveness," Holcombe notes. Principals were often left to judge the merits of a teacher by observations like whether the class was quiet and under control, how many children were sent to the office for misbehaving, how many kids passed the end-of-course tests that year and whether parents were happy. "It was very subjective," Holcombe notes.

After EVAAS became available to school systems across North Carolina, Guilford started using it to measure student improvement over time and identify students who might be overlooked for advanced math classes. Guilford County also uses EVAAS to increase academic growth among gifted and talented students.

As Guilford County began to look at the teacher effectiveness component of student success it immediately noticed that the best teachers were clustered in higher socioeconomic schools. In order to improve reading and math scores for third through eighth grades and passing rates for high school core classes, Guilford County wanted to draw highly effective teachers to schools with a higher percent of low-income students.

The results of the Mission Possible program have been dramatic. "We've been able to show significant increases in the percentage of students who are passing the elementary reading, math and high school subject tests in 97 percent of our program schools," Holcombe says. "We've had increases of 47 percent in some schools for certain courses. We've also decreased teacher attrition from 36 percent to as low as 10.7 percent."

We use EVAAS to attract effective teachers and to continue measuring their effectiveness.

Amy Holcombe
Executive Director of Talent Development

Teachers give it an 'A'

Teachers are not given a score based on one year’s worth of data, nor will they be penalized if their classes include a large number of children who arrive working below grade level. Instead, EVAAS measures each child’s growth from year to year. Growth data from all the students is pulled into the teacher’s effectiveness rating and over multiple years. A sixth-grade teacher’s effectiveness rating, for example, will include test score data from hundreds of students. "We don’t make judgments off one point of data," Holcombe says.

"Teachers who score below average [will] talk with their principal and their colleagues about their classroom practices [and] make changes to those practices. I’ve seen below-average teachers move to above average," Holcombe says. "Much like students strive to improve their performance, teachers now have a tool that indicates their level of performance."

Not just about measuring teacher effectiveness

Guilford’s first indication that EVAAS could make a dramatic difference came with an experiment several years ago at a middle school. The school looked at existing teacher effectiveness and student data for an incoming sixth grade class. It wanted to put the right teachers in the right subject areas and segment the students correctly. "The value-added data for that sixth grade in both reading and math was significantly above the district and state level," says Holcombe. "That was not the case for the seventh and eighth grades. They continued the practice for two more years and the result held true. No matter which class cohort came through, the sixth grade's approach to scheduling students and staffing teachers yielded better results than the seventh and eighth grades."

EVAAS is available to all the school districts in North Carolina through a statewide contract with SAS. Holcombe thinks this is a key reason North Carolina won a coveted $400 million US federal "Race to the Top" grant. North Carolina was one of 12 states to win a grant. "I don’t think any other state has such a robust teacher effectiveness data tool."


The school system wanted to measure teacher effectiveness fairly and accurately and entice highly qualified teachers to teach at low-income schools.


SAS® EVAAS® for K-12


  • Increased passing rates in 97% of program schools (upward of 47% in certain courses).
  • Dropped teacher attrition rate from 36% to 10.7% in some schools.
The results illustrated in this article are specific to the particular situations, business models, data input, and computing environments described herein. Each SAS customer’s experience is unique based on business and technical variables and all statements must be considered non-typical. Actual savings, results, and performance characteristics will vary depending on individual customer configurations and conditions. SAS does not guarantee or represent that every customer will achieve similar results. The only warranties for SAS products and services are those that are set forth in the express warranty statements in the written agreement for such products and services. Nothing herein should be construed as constituting an additional warranty. Customers have shared their successes with SAS as part of an agreed-upon contractual exchange or project success summarization following a successful implementation of SAS software. Brand and product names are trademarks of their respective companies.