Drop down behavior

Question

I see 3 types of behavior on the web for drop downs and I wanted to collect some insight.

When a user opens a drop down, I observe:

1. the user can scroll and the drop down stays open (bootstrap)

2. the user can not scroll, he is locked and needs to close the drop down by clicking somewhere else (safari and IE/edge)
3. the user can scroll but it will close the drop down automatically

As I have to dev an interface I was asking myself which behavior I should enforce.

Thanks,

Answer 1

I think if I was using your interface I would appreciate the drop-down staying open. Imagine this, I'm about to select some information in a drop-down, but it's some very "serious" stuff. I need to be careful to pick the right option. I then scroll up to check what was the question, any other info that could help me make an educated choice, etc. I return to your drop-down and behold, it's still open. I click on my option and move on to the next question/thing/whatever.

I know that that sounds like a small thing, but skipping that single step of reopening the drop-down could be really nice (that's all I could come up with really, still trying to learn how to justify speed in UX).

One more thing, please give the user freedom to at least scroll when they choose to. Whether you choose Option 1 or 3, just please don't impede the user from doing something they want to do. It's like punishing them for opening the drop-down.