The department has spent more than four months reviewing data and reports from districts that were flagged for suspicious scores on the annual exams known as the PSSAs, or Pennsylvania System of School Assessment.
Agency spokesman Tim Eller declined to confirm how many districts remain under review, but it could be about two dozen.
The statewide probe began last summer after a routine forensics report flagged results on the 2009 reading and math tests, which are given to students in grades 3 through 8 and grade 11.
The study by Minnesota-based Data Recognition Corp. used statistical analysis of answer patterns, erasure marks and student demographics to identify scores that could be considered "highly improbable." But it stressed that cheating was not necessarily the reason for the anomalies.
Nearly 90 schools were named in the report. Education Secretary Ronald Tomalis then ordered about 50 districts to conduct internal investigations and submit reports to him by Aug. 15.
Earlier this month, the department sent letters to 22 districts and six charter schools saying that no further investigation was necessary, Eller said.
Among the exonerated was the suburban Philadelphia district of Wallingford-Swarthmore. Superintendent Rich Noonan said Strath Haven High School was flagged for a spike in test results: Math scores jumped from 74.3 percent proficient in 2008 to 84.6 percent the next year; reading scores increased from 75 percent proficient to 90.2 percent.
The improvement was partly due to a new school policy that said 11th graders who did not score proficient would be enrolled in remedial classes, Noonan said.
"That was a huge motivator for our students because it prompted them to take the test more seriously than they ever had," he told The Associated Press on Wednesday.
Noonan also said the state had been aware of the district's improvement efforts because Wallingford-Swarthmore had been required to file a plan with the department for bettering scores among special education students.
He noted the school's results have remained largely consistent since 2009, and he criticized the state for taking so long to clear the district.
"It's been a frustrating experience to say the least," Noonan said.
Schools in Philadelphia, Hazleton and Connellsville were most frequently flagged in the forensic report. Connellsville was on the list of cleared schools, though Philadelphia and Hazleton were not.
Connellsville interim Superintendent Tammy Stern was not available for comment Wednesday.
