30.00% - Humans have a natural tendency to categorize things.
20.00% - Hoagies are sandwiches made with a roll that is split - not separated
20.00% - Any food made by putting fillings between bread is a sandwich
20.00% - Sandwiches are often cut in half to be more conveniently enjoyed.
10.00% - Sandwiches are more flat in shape, and shape is One defining characteristic of a sandwich.