First, the Election Complaints Commission took a sample of polling stations from around the country based on certain criteria that indicated fraud, such as more than 100 percent turnout at a station or a candidate receiving 95 percent of the vote in the Aug. 20 presidential election.
Then, the commission determined what percentage of the sample was fraudulent, and applied that percentage to the overall vote totals in affected polling stations, explained Scott Worden, one of the non-Afghan commissioners.
The investigation revealed that on average about 75 percent of the sample was fraudulent, which would disqualify hundreds of thousands of votes, said Worden.
The ECC decided to invalidate over 200 polling stations where there was "clear and convincing evidence of fraud," he said. "In fact, I think it's safe to say at the conclusion of our investigation there was in fact a great deal of fraud across the country."
Worden explains more, in this interview with NewsHour deputy senior producer Daniel Sagalyn:
Afghanistan's Independent Election Commission must still review the ECC's findings, calculate the exact number of votes that need to be invalidated, and then attach final percentages to President Hamid Karzai and second-place finisher Abdullah Abdullah to determine if a runoff should take place.
-- Interview conducted by Daniel Sagalyn of NewsHour