What does it mean when a female student of yours stares at the floor every time they see you in the halls and never acknowledges you?

Answer 1

I agree with Foofa, its not your concern that she avoids eye contact or acknowledging you outside of the class room. It could be that she's shy, introverted, self conscious. Or maybe she doesn't like you. Maybe she has things on her mind and isn't paying attention to others around her. Whatever it is, let it go.

Answer 2

Probably that she doesn't like you or feels intimidated by you. 

Answer 3

Is this your first year of teaching? Clear your mind. Your students need to pay a lot of attention to you while in your class. Not required to do so outside of your class hours or space. Not on the "need to do" agenda. Her "reasons" are immaterial. Don't give yourself the trouble of needing to know. You don't need to know. 

Answer 4

She's trying to be nonchalant. 

Answer 5

She is avoid eye contact 

Answer 6

She is an introvert.