I will be working for a big lab that requires secret clearance for some projects/information (defense contracts) handled. I was curious how commonly reference interviews and personal interviews occur for people needing secret clearances (I read that they aren’t mandatory for secrets but do happen).
I don’t know for sure but reading from this forum and my personal experience, usually if you are a naturalized citizen, travel abroad a lot, with many foreign contacts; the interviews will be conducted. Another thing is your past behavior such as drug use, etc.
In my case I had 5 hours interview and my references had personal interview at their residence.
How often isn’t the question because it’s not a random selection. The question to ask is: What triggers a mandatory investigation?
I went through the Secret clearance process 11 years ago. No one on my SF-86 was contacted. Hope this helps.
I will share my experience. I worked with a naturalized citizen who had his personal refences interviewed, or at least one that I know of, was interviewed for a secret. I am a citizen by birth and none of my references were interviewed. However, I cannot say that his were interviewed and mine not because he was naturalized and I was birth. I had a personal interview for secret and I know of naturalized citizens who received their clearance without a personal interview.