If I skim through a book, I won’t consider it read. If I read the summary through a wiki article OR online notes, I also have not read it.

If I’m reading for pleasure, I should be enjoying reading the book as a whole—if I skip chapters or skim it: that book would have not been very good for me and I won’t finish reading it. And I won’t put it on my list of read books. I’ll just pick another until I find one that can keep me entertained through and through.

I completely skim when I revisit my favorites though. Especially when I just want to go back to a particular part.