This is a concept I only really began to understand around a year ago. I would hear it used frequently in the community but have had a lot of difficulty comprehending and applying it. I keep coming back to it because I feel like it is an important skill.

One effect of qualifying is that it shows the girl you don't need her. By having standards and testing to see if she meets them you show her that you have enough experience with women that you know what you are looking for. When you know what you're looking for (and I mean more specific than just "hot" lol) you won't just settle for any girl... even if she is hot.

Another effect is that it makes her feel special. By making her jump through hoops she feels like she has proven herself as worthy to a high status man. Girls like to feel special and work to earn a guy's approval.

It is also important because it makes you as a man feel more in control of the situation. It puts you into a different frame of mind. A frame I used to permanently exist in was "I hope she likes me". When you qualify the frame is changed to "let's see if she's cool or not". This is a good confidence booster and sets the initial tone of the interaction as the man being the higher status person.

Example of qualifying:

Guy: "What kind of books do you read?"

Girl: "I dont read lol"

Guy: "Oh you don't read. I'm only interested in girls who read."

Girl: "I used to read in school though! I read Harry Potter when I was a kid! I really want to start again!"

A key here though is that you have a lot of the non-verbal high status behaviors down first. If you try the lines above but your voice is weak, your chest is caved, your eyes are shifty, and you're leaning in, it just won't work.

This is a big caveat because the non-verbals are a lot of work to get good at whereas qualifying a girl with the above lines is easy. Qualifying therefore is just a way to lure a girl into your high status world with minimal effort. If you don't have a high status world qualifying just won't work.