A tense showdown between Shelby County Schools officials and local charter operators Wednesday came down to a basic question: Should charter schools be held accountable for keeping their promises?

The national charter movement began with a resounding yes to that question. The idea was that schools could more easily deliver strong academic results if they were free from some regulations. The flip-side was that schools that could not fulfill their promises should not get to stay open.

But as the movement has matured, that theory has been tested repeatedly when schools do not measure up to their own goals. Across the country, efforts to shutter low-performing charter schools have ended in challenge — sometimes practical, such as when there are not better schools for students to attend, and sometimes legal.

That dynamic played out Wednesday during a State Board of Education hearing about Shelby County board’s decision to revoke three Memphis schools’ charters, saying that they had not delivered the results they promised. The three schools — Omni Prep Academy Lower School, Omni Prep Academy Middle School and Southern Avenue Middle School — quickly appealed the April decision, arguing that they had not been given sufficient warning that they were at risk.

They repeated those arguments during the hearing. (A fourth Memphis charter school that Shelby County has moved to close, New Consortium School of Law and Business, presented its case earlier this month.)

“No one has ever heard of being held accountable over established goals,” said Omni Prep’s CEO, Marc Willis. He suggested that Shelby County was closing the schools to address its own budget gap by returning their students, and their associated funding, to the district.

But Shelby County Schools’ chief innovation officer, Brad Leon, noted that Omni Prep had faced off against the district before, when it turned down the network’s bid to open a new school — and said the resulting appeal to the state proved that Omni Prep officials knew well what was expected of them.

“We were all sitting in this room together, as late as September 2015, going over the same data and performance concerns,” Leon said. “The contention that no notice was provided is inaccurate.”

How Shelby County authorizes charter schools makes accountability complicated. The applications that charter schools submit in order to open loosely serve as the schools’ contracts with their local district, and they include projected academic results. Schools that want a formal contract must pay a fee to the district.

That leaves some schools with legally binding obligations and others, including Omni Prep and Southern Avenue, with less formal promises. The district also does not have any official criteria, academic or otherwise, governing charter revocation — something that charter advocates are demanding to change.

But last year, Tennessee lawmakers passed legislation that allows charter authorizers to revoke charters of schools whose test scores put them in the bottom 5 percent statewide.

Though that law will not go into effect until 2017, Shelby County officials have invoked the principles behind it in explaining the four closures.

“Do you actually want to lower your own standards?” Leon said in an interview. “We want them to achieve their goals, of course. But when you tell the public, ‘This is what we’re doing’…we’re taking you at your word.”

State board executive director Sara Heyburn is expected to issue recommendations on each charter school’s appeal by next week. The State Board will vote separately on all four schools’ appeals during a special meeting in Nashville on May 27.