The Pennsylvania investigation is only a few weeks old, far too early to judge. But the first step is not encouraging: State officials have directed school districts and charter schools with suspicious results to investigate themselves.

For places that are serious about exposing cheating, there is a new gold standard: Atlanta. In the bad old days, Atlanta school officials repeatedly investigated themselves and found they had done nothing wrong. Then, last August, the governor decided that, once and for all, he was going to get to the bottom of things, and appointed two former prosecutors to oversee an inquiry.

Sixty of Georgia’s finest criminal investigators spent 10 months on it, and in the end turned up a major cheating scandal involving 178 teachers and principals — 82 of whom confessed — at 44 Atlanta schools, nearly half the district.

Will Pennsylvania do an Atlanta? It’s a big commitment. First, schools with test score gains that seem too good to be true need to be identified. The Philadelphia Inquirer has looked at Roosevelt Middle School, where 63.8 percent of eighth graders were proficient in reading in 2009, compared with 28.9 percent in 2008.

Next, to get a sense of the scope of the cheating — there are 3,300 schools in Pennsylvania — a comprehensive erasure analysis is needed. In Atlanta, investigators calculated erasure rates for every teacher in the district.

In Pennsylvania, the 2009 statistical analysis that was unearthed by The Notebook has provided many good leads. Chester Community Charter, one of the state’s biggest schools, with 2,700 students, was among those most often flagged for suspicious erasure results. It also was flagged for questionable test scores: in 2009, 65.4 percent of eighth graders were proficient in math, compared with 22 percent the year before. To his credit, the state’s secretary of education, Ron Tomalis, has requested two more statistical studies, for 2010 and 2011, to better identify cheating patterns.

Once the questionable schools have been pinpointed, the serious work begins. In Atlanta, the investigators chosen to conduct the cheating inquiry were given the necessary legal tools (subpoena power) and generous resources (over 100 people were involved). Then they went out and worked the schools like police detectives, flipping one cheating teacher, who in turn would identify others.