Louisiana’s top school board will be told Tuesday that the state needs to make major changes in how it rates public schools.

“With these changes Louisiana would have one of the best accountability systems in the country,” according to a report written by Tulane associate professor of economics Douglas N. Harris, who was asked to review oversight methods.

A committee of the state Board of Elementary and Secondary Education is set to discuss the study on Tuesday at 9 a.m.

Harris is recommending that the state:

  • Overhaul the annual public school performance scores, which are linked to letter grades, so yearly student academic growth accounts for half of the score. The tallies are now based on the percentage of students who reach various performance levels.
  • Add more letter grades — pluses and minuses — so schools have new incentives to improve.
  • Remove the requirement that teachers be rated as “ineffective” if they fall into that category on either the objective or subjective part of the annual reviews.

Harris also recommended a full-scale, third-party evaluation of the state’s public school accountability system focused on comments from educators and student outcomes.

Whether any or all of the suggestions will be acted on is unclear.

The state’s accountability systems include laws and policies enacted over years, often amid fierce debates.

The review was prompted by BESE.

Jessica Baghian, assistant superintendent of education, said Monday that Harris’ study is part of a wide-ranging look at public school operations.

“I just think it is an academic view on how to move forward,” Baghian said. “We appreciate the perspective.”

Harris said in his study that while Louisiana’s accountability system has its strengths, “it also has weaknesses that undermine quality instruction and student outcomes.”

He wrote that school performance scores, which are mostly based on how students fare on key tests, “does a poor job of measuring what schools contribute to student learning.”

Rating schools based on student performance levels “mainly reflect the achievement levels of students when they started school, not how well their recent teachers taught them,” according to the report.

“Yet student growth is now almost absent from the (school performance score),” the study says, a reference to scores that make up a school’s letter grade.

“The state should aim for a 50-50 split between growth and achievement levels.”

Doing so also would better align school scores with annual teacher evaluations, where the growth of student achievement accounts for half of the job review, Harris wrote.

Under current rules, the state’s roughly 1,300 public schools are assigned letter grades on a 150-point scale based on their school performance scores — A, B, C, D or F.

“Schools in the middle of the categories have little incentive to take additional steps because moving the SPS the equivalent of half a letter grade is extremely difficult,” the study says.

Harris wrote that adding pluses and minuses to the grades “allows for greater nuance while maintaining the basic intuition that letter grades provide.”

Follow Will Sentell on Twitter, @WillSentell. For more coverage of Louisiana government and politics, follow our Politics blog at http://blogs.theadvocate.com/politicsblog.