Hosanna Mahaley, state superintendent for education in the District of Columbia, said last week city officials are “committed to restoring and improving confidence” in standardized test security. Yet what they are doing will achieve the opposite.

Since USA Today last year exposed unusual numbers of wrong-to-right erasures on D.C. Comprehensive Assessment System tests in more than 100 schools, many parents and teachers have been waiting for a deep, tough investigation.

Elementary and middle school kids taking an exam don’t suddenly realize that several of their answers are wrong and erase to make them right. What they know or don’t know rarely changes during a test. Yet the USA Today project (conceived and edited by my wife) found that D.C. classrooms sometimes had 10 times as many wrong-to-right erasures per child as was normal. Educators familiar with testing say it is likely that school administrators in at least some cases tampered with answer sheets after children went home.

Many people assumed school officials would question teachers and principals closely and compare their statements to what students remembered. The long-term reputation of the school system was at stake.

When similar erasure data was found in Atlanta, Georgia’s governor ordered state investigators to question educators under penalty of criminal charges. They found wrongdoing in 44 schools. The state forced the removal or resignation of many principals found to have tampered with tests themselves or colluded with teachers.

In D.C., however, Schools Chancellor Kaya Henderson last spring handed the investigation of 2009 and 2010 scores over to D.C. Inspector General Charles J. Willoughby. He seems to have devoted few resources to the investigation and has not yet released a report.

Last week, Mahaley’s office said it had reduced from 128 to 35 the number of classrooms it will ask an independent contractor to investigate in connection with 2011 tests. Its criteria for the probe will make identification of tampering by administrators more difficult.

As reported by my colleague Bill Turque, just having an unusual number of wrong-to-right erasures will not guarantee a close look. A classroom will only be investigated if it also has big test score gains by individual students from 2010 to 2011, wide variances or unusual patterns of scores within the classroom, and test results from the prior year that showed inordinate wrong-to-right erasures in that teacher’s classroom.

This approach focuses on possible wrongdoing by individual teachers and narrows the period of time that can be examined. It overlooks the possibility of tampering by principals and test directors over several years. Some erasure outbreaks were found as early as 2008. If a school had a big improvement in test scores in 2008, 2009 or 2010 and stayed at that high level by continued tampering, there would be no suspicious rise in scores from 2010 to 2011 and thus no reason to investigate under these rules.

The city should have investigators interview principals, test directors and teachers under threat of criminal sanctions if they do not tell the truth. Asking students what they remembered would also help: Did they actually check their work and make erasures?

It appears that is not going to happen in the District. Mahaley’s office said it consulted with independent test security experts in deciding on the criteria. I spoke to one of those experts and reviewed the resumes of the others. None appear to have any experience investigating the large-scale cheating that seems likely to have happened here and did occur in Atlanta. The consultants’ experience is in isolated cases of cheating by students and teachers, not relevant to wrong-to-right erasure numbers this numerous and in so many schools. A Mahaley spokesman said erasures alone don’t indicate impropriety.

Will we ever discover what happened after hours to the D.C. answer sheets kept in cabinets to which principals had the keys? Will D.C. parents ever have proof that the people running their neighborhood schools can be trusted? I doubt it. The impact of ignoring the inflated scores will be disastrous. I wonder why the people in charge don’t see that.