There was that recent event of a NOLS group apparently surprising a bear in AK which made national news. But I think in general that statement about groups of 3 or 4 being less likely to draw an attack from a bear seem valid, possibly because of the noise or smell. My wife and I want to go to the Canadian Rockies next summer and it is suggested to go out in groups of at least when hiking. We will be alone on our 25th anniversary so I am not sure how we are going to do this at this point in time.

Bill, I think you hit the mark when you point out how most people have their head down when hiking and are just focused on getting somewhere. Bound to be some collisions if you are not making noise and not really focused on what is going on around you.