Recently I submitted a paper to an IEEE conference. A week after the notification deadline, I haven't heard anything from the committee yet, so I decided to email the Technical Program Chair directly. They told me that 80% of authors have been notified, the rest have to wait a bit more.
I'm not sure how is that possible, sice the quota for accepted paper is limited and the committee should make all decisions at once? For the 20% authors haven't received notifications, is the acceptance rate for them higher?