I am 5'1 with average sized legs and these, size 9-13, barely cover my kneecap when pulled tight.  The top does roll badly, but that wouldn't be a big deal if they were full length over-the-knee socks.  They have very little give and aren't particularly comfortable, so ultimately there is nothing at all to recommend these socks.  If you have extremely long thin legs and have trouble finding knee-socks, maybe these are for you.