Nobody was particularly surprised when the D.C. Inspector General’s Office, after a 17-month investigation into allegations of widespread cheating on standardized tests in D.C. public schools, issued a new report which concluded that the suspicions were unfounded.

Kaya Henderson and Michelle Rhee (Ricky Carioti/WASHINGTON POST)

Thus it isn’t exactly clear how Inspector General Charles J. Willoughby came to that conclusion.

Investigators only delved into cheating suspicions at Noyes, where big gains on scores were reported during the time that Michelle Rhee was schools chancellor and linked student test scores to the evaluations of some teachers. Willoughby’s team found that at least one teacher had cheated, and decided that because they found so little fire amid the smoke, there was no reason to look at any other schools, the report said.

Yes, that’s what they found after 17 months of work.

Incidentally a different probe into the USA Today allegations, conducted by Office of the State Superintendent in the District, found that teachers at three schools had cheated.

The investigators working for the D.C. Inspector General seemed to swallow the idea that kids make a lot of changes to their answers on standardized tests that don’t actually affect them personally. And they didn’t talk to any students, who would have been able to tell them if they had, in fact, made a lot of changes to their answers during the tests.

The new report actually says that “much of the information obtained throughout our review of Noyes... is applicable to other DCPS schools.”

How would the investigators know if they didn’t look?

If they really wanted to know what was going on around the system, they could have subpoenaed everybody potentially involved and had them testify under oath. They chose not to.

Of course, there is a history in Washington, D.C., of cheating allegations — and less than a determined effort to get to the bottom of it. Back in 2009, my colleague Bill Turque wrote about an investigation into possible cheating at 26 public and public charter schools where reading and math scores had shot up in 2008. The suspicions were never thoroughly investigated by the Rhee administration.

The report does include a long list of recommendations for school officials to help avoid cheating in the future, including increasing the number of proctors monitoring test applications and ensuring that teachers don’t watch over their own students. The recommendations are not binding.

Rhee’s successor, Chancellor Kaya Henderson, has said she wanted to get to the bottom of the allegations, but neither she, not D.C. Mayor Vincent Gray, nor his predecessor, Adrian Fenty, did much to make sure there was a deep district-wide investigation into cheating.

Bob Schaeffer, public education director of the National Center for Fair & Open Testing, or FairTest, says the only cases nationwide in which cheating has been fully documented are when truly independent investigators were brought in.

Despite the many cheating scandals around the country — including two major ones in Georgia that were exposed by an investigative team working for the governor — you don’t hear school reformers calling loudly for these cheating accusations to be seriously investigated.

This is not to say they condone the cheating; surely none of them does. But at the very least, the scandals are distracting for them, and at the very worst, they would undermine the central mechanism of their standardized test-based “accountability” movement. There is a bias toward believing even insufficient investigations that find little cheating.

Cheating scandals have been reported for years but whether or not cheating has occurred on high-stakes standardized tests, and how much, matters more than ever. Today the scores on these assessments are being used to grade students, schools, teachers and even whole districts.

Many educators say that the pressure on them to raise students’ test scores has led to more cheating. Though that doesn’t excuse the behavior, it explains it. And cheating is only going to get worse as even higher stakes are wrongly placed on standardized test scores. The only question is whether the public will ever find out the extent of it.

Follow The Answer Sheet every day by bookmarking .