How would you determine open-mindedness?

Patience and the willingness to understand others perspectives

I view it as having tolerance of all others. Regardless of age. Sex. Religion. Nationality. Etc. We can be different and still be open and accepting. We don't have to agree, but we do need to respect.

Possessing a willingness to try new things or to hear and consider new ideas, and a willingness to be accepting of all people without bias.

Knowing that right and wrong don’t exist. Just different perspectives on the same matter.

Someone who does not automatically reject certain ideas, activities, cultures, etc. without listening and evaluating with their mind clear of any pre-conceived notions.
It does not mean that once you evaluate you would do anything, or allow anything. It just means you will make your own decision based on that one instance.

tolerance
respect others as you want to be respected yourself

A sense of adventure and compassion.

Evaluating it with an open mind...😀

Brain surgery?! 😘

Flexibility

I think orwell expressed it best... The ability to hold two competing ideas in your head and believe in them both

By gauging the objectivity in responses coz nothing is in only no or yes.

Open to many ideas and views

It is always if they agree with me.... 🙄 😉

Being willing to learn and experience new things and being willing to accept that you might be wrong about something.