This is the fourth in a series of four videos about the bubble sort. This video shows two techniques that can be used to improve the efficiency of a bubble sort procedure implemented in Visual Basic.NET. The first enhancement involves reducing the number of comparisons made by one, each time the unsorted list is scanned; this means that the enhanced bubble sort performs half as many tests in total. The second enhancement exploits the fact that if the list is scanned and no swaps are necessary, then all of the data must now be in the correct order, and so an early exit from the bubble sort procedure is forced.