The whole top and bottom is, most women do not like to reject and they go about rejecting in the kindest way possible and so as not to hurt feelings...it's just the way we are and I guess that can lead to confusion for guys. What women should say is 'Look...you repulse me, I would never date you in a million years, leave me the fck alone'!!!! LOL
If a woman is into you and I mean a 'woman' not a girl, she will rarely play 'hard to get'. She will be reciprocative of your advances and you would never have to second guess her interest.
A woman who is half hearted or not sure about you, might not make herself as available to you as the really interested woman would and because she's trying to figure it out....that isn't playing hard to get, although it may be perceived that she is. You would know if there was some kind of interest and because she doesn't always make an excuse to cancel your dates and so continue to pursue her if that is what you want to do.
The woman who is totally not into you, will be unavailable and make excuses time after time and to the guy who doesn't appear to be getting the message. I'm unsure why 'no interest' is so difficult for men to read or for you to accept....because I'd know if a guy wasn't interested in me and I'd move on.