A sequence class differs from the author's bag class in that items in the sequence the order of the objects has nothing to do with the distinction between these two things. are always in order are kept in order as dictated by the comparison operators of the datatype being stored are kept in the same order as what the programmer put them The bubble sort can out-perform the selection sort because it has a Big O of Log_2 N. because it does less swapping of values. bubbles move faster through the computer's memory if the array is already partially sorted