Perception that examiners are inclined to allow claims. Although this
perception cannot be quantified, it is prevalent and therefore should
be addressed. The statistics provided above show that while it is rare
that reexamination results in full cancellation of all claims, in the
majority of cases the claims are initially rejected and then amended.
(64% of ex parte reexaminations result in claim amendments;10%
result in all claims being canceled.
From :
THE USE OF INTER PARTES AND EX PARTE
REEXAMINATION IN PATENT LITIGATION