I'm an experienced searcher and computer user. But I do not understand why Google seems to consistently do OR searches, when it claims to do AND searches (see, for expl, the Advanced search page).
EXAMPLE (one of dozens I could provide): I searched for Mark Twain sayings , and was told thee were about 965,000 hits. Then I added the word reputation , looking for any quotes from Twain that had that word in them--and was told three were 25,800,000 hits!
How could that be? Adding the word reputation to a search that produced 965,000 hits should narrow the search and produce FEWER results.
This happens consistently, with almost all the searches I do.