Looking at Other Measures of Performance: The Assessment Index Versus the School Performance Score

As we discussed in our last post, school performance under Louisiana’s accountability system can be measured a number of ways.  In addition to the state-assigned School Performance Score (SPS) and data on student proficiency on standardized tests, schools also receive an Assessment Index.  Each of these measures has its pros and cons when being considered as an accurate assessment of a school’s performance.  While our last post contrasted schools’ SPS with their LEAP, GEE and iLEAP scores, we do the same here for the SPS and the AI.  It should be noted, however, that regardless of what measurement we consider, the fact remains that on average New Orleans public schools continue to improve each year.

School Performance Scores
The School Performance Score, calculated by the Louisiana Department of Education (LDE) is used as a measure of absolute school performance and as a means of calculating the growth schools need to achieve in order to make Adequate Yearly Progress under the No Child Left Behind Act.  It is based on students’ test scores on all of the state tests (LEAP, iLEAP, and GEE), drop-out rates, and attendance.  This number is frequently used by education stakeholders and the media as an accurate and complete measure of a school or district’s performance.

A school’s Baseline SPS is calculated by averaging the previous two years of school performance data and is used to give a school a performance rating label.  Scores range from 0.0 to 236.4 or 266.7, depending on a school’s grade configuration.  The Department of Education gives a school with an SPS of 60 or the performance label “Academically Unacceptable,” and considers it a “failing” school.  Two years of data are used to even out dramatic growth or decline in a single year in order to provide a more accurate estimate of a school’s performance over time.

The 2009 scores revealed that schools have continued their pre- and post-Katrina trajectory, improving steadily each year.  Out of the New Orleans public schools receiving an SPS score for the 2007-2008 school year, 54.7 percent had an SPS above 60.  In 2008-2009, this went up to 58 percent of schools in comparison to the approximately 37 percent above 60 in 2004-2005.  Were all schools in New Orleans part of a single district, the District Performance Score (DPS) for 2008-2009 would be 70.6, an improvement of 4.2 points over the 2007-2008 DPS of 66.4.

Because so many New Orleans public schools are in their first and second years of operation, data in the following table reflects only the 52 schools for which a Baseline SPS was available for 2007-2008 and 2008-2009.  For 2008-2009, 14 of 86 open schools, or about 16 percent, did not receive a Baseline SPS.

Despite significant improvements in the percentage of students reaching proficiency on the LEAP and GEE tests, the averaged SPS growth of RSD-run schools was only .5 points.  According to the LDE, this is due to the difficulty in gathering accurate attendance data at RSD-run schools, which have a highly mobile student population and continuously enroll students throughout the year.

Assessment Indices
While analysis of New Orleans’ schools’ SPS reveals that schools and the system as a whole are improving, this number might not accurately reflect the growth in student achievement over the course of a year.  Using a school’s SPS as a marker of school quality may be valuable over the long term but growth or decline in this area can mask short-term gains or declines in achievement on standardized tests, as the minimal SPS growth of the RSD-run schools demonstrates.

A more accurate way to measure the extent to which these schools are improving academically, as measured by all standardized tests taken by students, over the course of a year may be to use the Assessment Index.  The AI is calculated in a manner similar to the SPS, though it uses only one year of data.  AIs for schools with Kindergarten through 8^th grades are based strictly on student test scores and not attendance and graduation rates like the SPS.  High schools’ scores are calculated using a “dropout adjustment factor” to account for students who left school before taking standardized tests.

Comparing a school’s prior and current AIs is a more straightforward way of analyzing short-term academic growth which is important given that most schools in New Orleans have no more than three years of post-Katrina student performance data available.  When growth is considered this way, it appears that all types of schools improved student achievement significantly more than their average SPS scores would seem to indicate.

Click here for a breakdown of each school’s 2008 and 2009 AI and growth.