Dr. Beverly Hall, center, arrives for her last Atlanta school board meeting at the Atlanta Public Schools headquarters in Atlanta on June 13, 2011. Hall and nearly three dozen other administrators, teachers, principals and other educators were indicted Friday, March 29, 2013, in one of the nation's largest cheating scandals. (Curtis Compton/AP)

It’s not every week that a parade of public-school educators reports to jail.

But that’s what happened when, in the early hours of Tuesday morning, the first defendants in the Atlanta Public Schools cheating scandal — reportedly the largest in this country’s history — began surrendering to authorities. Over the course of two days, all 35 of the teachers, administrators and testing coordinators named in a 65-count indictment were booked into Atlanta’s Fulton County Jail. Among them was Beverly Hall, the former Atlanta schools superintendent who led the district during the alleged scandal.

The educators are accused of racketeering, theft, conspiracy, making false statements and influencing witnesses. Amid the allegations, much has been made of Hall’s “insular style and her isolation from the rank-and-file,” as the 2011 investigative report stated, as well as the environment she and her subordinates created “where achieving the desired end result was more important than the students’ education,” as the indictment reads. Prosecutors charge that Hall, who has denied the allegations and any involvement in the scandal or other wrongdoing, put “unreasonable pressure” on employees to reach high targets on standardized test scores, which led to cheating by teachers, principals and other employees.

The breadth and severity of the scandal is deeply disturbing and, if the allegations are true, the failure of leadership that contributed to it is shameful. But as unsettling as the Atlanta case may be, here’s the thing: It was probably bound to happen somewhere, if not on such a massive scale. Take an overly simplistic set of measurements, add sizeable monetary rewards, throw in human failings, and you have a recipe for gaming the system.

That’s particularly true when it comes to something as hard to measure as the performance of teachers and public schools. As behavioral economist Dan Ariely wrote for On Leadership when the scandal in Atlanta first made national headlines nearly two years ago, “once we measure something we make it salient and motivational, and people start over-focusing on it and neglecting other aspects of their job or life.” When that something is as intricate and complex as what makes a good teacher or a well-performing school, reducing it “to a simple measurement, and then [basing] teacher pay primarily on it, has a lot of negative consequences.”

That’s why it’s important not just to get rid of the “cheats who need to go” (as The New York Times called educators who were part of the scandal in Atlanta and other cities) but the simplistic measurements of teacher and school performance that have been designed to motivate them. In an op-ed in the Post on Thursday, Microsoft founder and philanthropist Bill Gates wrote that “what the country needs are thoughtfully developed teacher evaluation systems that include multiple measures of performance, such as student surveys, classroom observations by experienced colleagues and student test results.”

As if on cue, the Atlanta Journal-Constitution reported Thursday that Georgia’s Department of Education intends to roll out a new “performance index” that will grade its schools on a number of factors, including graduation rate, school attendance and academic progress.

Who knows how well such changes will prevent future scandals. Much will depend on the integrity of the leaders who are put in place, of course. But it will also depend on how well those new grades are tied to rewards. Teachers, principals and administrators will need to see how their own performance can influence the grades, trust that the right factors are getting evaluated, and be assured that no single measurement is getting too much weight.

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