This post from Dennis Crouch points out a significant shift in the USPTO of a greater percentage of primary xxaminers. He praises this change because examination with primary examiners is more efficient and effective. Assistant examiners have someone "looking over their shoulder," resulting in longer examinations and fewer allowances.
Specifically, Professor Crouch pointed out that having a primary examiner enables direct negotiation with the decision maker. He says primaries reach the "crux of prosecution" faster than assistant examiners. Crouch also points to recent data that shows allowance rates are higher with primary examiners.
In my 27 years of experience interacting with examiners, I have found that not all examiners are created equal. Interviewing examiners, in my view, is the best way of working with them. Also, avoiding an adversarial approach is paramount to achieving a successful result.
Prior to 2015, over 35% of patents were examined by assistant examiners. Since 2020, this number has plummeted to less than 20%. But these assistant examiners did not simply disappear. For the most part, they rose in rank and became primary examiners.
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