The author reports on a state investigation into Atlanta's impressive gains on state tests which finds that test-tampering was rampant in the much-praised school system. The report unveiled by the Georgia governor's office states that Atlanta teachers and principals for years methodically altered answer sheets for students taking state tests, boosting scores and transforming struggling schools--and the district as a whole--into what appeared to be a spectacular urban success story. The investigative team drew on more than 2,100 interviews and examined more than 800,000 documents as part of its nearly yearlong probe into improbably high test scores across the 48,000-student district. Apparently one of the largest cases of alleged cheating on state exams to date, the scandal shines a harsh spotlight on the much-lauded district and is expected to fan debate over the validity and effectiveness of high-stakes testing-and-accountability systems. The findings also bring a disturbing coda to the career of former Superintendent Beverly L. Hall, who retired in June after 12 years in that job, and was at the helm of the district when the cheating was alleged to have occurred. The report says that Ms. Hall and her top staff must have known that cheating was taking place, because of the unusually high gains and the word of whistleblowers.