We create the EEI as follows:


  1.  Looking at data for students who qualify for free and reduced-price lunch (FRL), we measure the percent of those students that score proficient or above on state standardized tests in their respective grade.
  2. To make the results nationally comparable, we adjust the percent proficient based on the difference between FRL average proficiency on the National Assessment of Educational Progress (NAEP) and the FRL average proficiency on each state’s standardized test. This results in a measure that is an estimate of the “percent proficient” a school or city would have gotten on the NAEP had all of the FRL students taken the NAEP that year.
  3. We then categorize schools and cities based on how their FRL proficiency level compares to all students nationally, creating four categories, called Low-income Achievement Categories:
    • Red: The average low-income student in this school or city is performing below the average of all low-income students nationally
    • Orange: The average low-income student in this school or city is performing above the national average for low-income students, but below the average of all students nationally
    • Yellow: The average low-income student in this school or city is performing above the average of all students nationally but below the national average for non-low-income students
    • Green: The average low-income student in this school or city is exceeding the national average performance for non-low-income students.
  4. We make an adjustment for the concentration of students at each school who qualify for FRL, in order to account for the known correlation between poverty and academic performance.
  5. We convert the adjusted scores for each grade and subject into percentiles on a 0 to 100 scale, with 100 being the best.
  6. We use a weighted average of the percentiles for all grades and subjects tested within a given school or city to arrive at the EEI Score, on a 0-100 scale. Lastly, we group the EEI Scores into 5 categories to provide a snapshot comparison. The categories are far below average (1-10), below average (11-30), average (31-69), above average (70-89) and far above average (90-100).

For a more detailed methodology technical document, please email ldauter@greatschools.org.