buy a bear peper-spray. if the bear gets too close (they approach slowly and display lack of interest before they charge), that can help. also honking cans can scare them away. if you get to close to them by mistake, they get scared and charge to scare you: stand your ground and slowly back away, but don't turn your back to them. if they get close to you after you saw them, they prepare to charge and get you; fight with everything you can (rocks wood etc); never turn your back on them or run; there is an excellent video at burnaby public library explaining bear behaviour, what to do, and stories from people that made it through a bear attack.
if the bear gets you after a charge to scare, you have a chance playing dead;
if the bear gets you for food, screeming can get somebody to help and scare the bear away; it will run away if if didnt kill you yet.