D.C. Schools Chancellor Kaya Henderson called Tuesday for national standards to guide educators in investigating claims of cheating on standardized tests, contending that without them, school districts will continue to be second-guessed in their efforts to probe and punish such misconduct.

“Because there is no standard either for identifying potential wrongdoing or for investigating once cheating is alleged, we are left with a fuzzy picture of what reliable outcomes are,” Henderson said at a U.S. Education Department symposium on test integrity.

Henderson’s comments come in the midst of an inquiry into alleged cheating by District educators on the DC CAS between 2008 and 2010. She asked the D.C. inspector general to investigate after USA Today published a lengthy investigation in March that revealed elevated levels of answer sheet erasures, in which wrong responses were changed to correct ones, at more than 100 schools. The U.S. Education Department’s inspector general later joined the probe.

But Henderson suggested that absent clear guidelines, the findings from these inquiries likely would not quell questions from the public or the media about the sharp improvement in D.C. test scores under Henderson’s predecessor, Michelle Rhee. She said school systems would remain vulnerable to attack from “those who would like to tear down outcome-based education reform.”

Since taking the chancellor post on a permanent basis a year ago, Henderson has generally avoided the national spotlight, avoiding the sharp rhetoric that marked Rhee’s tenure. But she expressed unmistakable exasperation Tuesday with recent commentary and criticism on the cheating issue.

District of Columbia Public Schools Chancellor Kaya Henderson speaks with the D.C. council members at her confirmation hearing in Washington on June 16, 2011. (Marvin Joseph/The Washington Post)

“Should we investigate every classroom with an above-average level of erasures, knowing this would force us to investigate half of all our classrooms and only catch one form of cheating? Henderson asked. “Should we investigate classrooms where there are high levels of [test score] growth knowing this would place a huge burden on our absolute highest-performing teachers, the very ones we want to reward and keep in our classrooms? If we’re going to use any of these measures, how many standard deviations above the mean does one need to be to warrant an investigation?”

Henderson said DCPS took every conceivable step in response to questions about test security, including hiring a private firm, Caveon, to investigate high-erasure classrooms flagged by state authorities in 2009 and 2010. She called out the media for fanning the controversy.

“It was easy sport for the press to play the what-more-could-be-done game,” she said. “Couldn’t we have looked at right-to-wrong erasures in more schools? Wasn’t there more that our vendor could have done to identify inconsistencies?”

Henderson said the answer to all the questions was “yes.”

“But there was no reason to believe that any of these actions would have yielded more-reliable results or more-accurate results,” Henderson said. “It was clear to me it would be very easy for a district like ours to fall down a rabbit hole of testing investigations only to find out that because there are no widely accepted standards, there is no agreed-upon result that would have satisfied the press or the public.”