But what if she is just shy? How can you be so sure that all girls show interest in the same way or even show interest at all? Personally, when I like a girl, I try really hard to not give her the impression I am interested because I don't want to make things awkward. But like I said, I have noticed her looking in my direction before.

I don't really like the whole "women send out signals" thing. I find that it implies men are responsible for reading women and only approaching them when we know they are interested. That is the type of behavior that feminists like to promote because it limits our ability to pursue women we like. Instead we are limited to the women whom we know from school or work or friends or online dating sites.

We are not mind readers and should not be expected to know when someone is interested in us before we've even talked to them. Not to mention, often times women are not interested in a guy initially but become interested after getting to know him.