I'm introducing a class to ArcGIS Online. I'd like to make a simple map of our campus, where each person in the class can post and share their favorite eating places ON JUST ONE MAP. How do I make this happen? They've all got public accounts, and I've even been able to create a group for them. Can I make a layer that they can all edit? Would it be better for them to each make a layer and then share to the group? Thanks so much for any insight!