At the very least I will skim to the end. I rarely just stop reading a book halfway through. Sometimes I stop reading a book towards the beginning if it's just not holding my interest, like I did recently with Gone With the Wind. Usually that isn't because I don't like a book, it's just not the right time for me to read it. For some reason I'm more adamant about books I don't like and I really try to keep reading them to see if they ever get better. I can only think of two books I've read in the past year where I wanted to quit reading them. Surviving Paradise I skim until about the 3/4 mark and then put it aside. It was during a very busy time for me and I decided I just didn't have time to spend skimming a book I wasn't enjoying. The other book was Secret History of the Pink Carnation, which I skimmed to the end and read certain parts of.