POPA Reports on Patent Quality Reviews
Their table of results by technology center (reprinted by the Patently-O Blog) indicates that the average error rate is still less than 5%.
"More than 30 percent of the Quality Review findings were reversed or dropped.
Approximately another 9 percent were "modified" or determined not to be examiner error, but also not quality reviewers' error.
"Compare this to the acceptable error rates imposed on patent examiners by the USPTO: An error rate of 4.5 percent or greater results in a less than fully-successful rating. An error rate of greater than 7 percent can lead to an examiner's termination.
"The decisions are wholly subjectiveâ€”the quality reviewers and the technology center staff who decide each case determine which cases are labeled as errors and which are not. Given the same case and the same facts, different reviewers can and do find opposite results.