Summary of Class Presentation for September 7, 1999

	Topic:  Object-Oriented Divide and Conquer Design Method - part 2

	We continued with steps 4 and 5 of the design method begun in the
last class.  These steps are closely related:
	4.  Determine the major ways in which the product might be used 
		by different types of potential users:
		a.  try to determine the different types of users and
			their reasons for using this product:
		b.  From those reasons or goals, figure out the major 
			uses for this product;
		c.  check this information with your potential users
	5.  FOR each potential use identified in 4, determine how the 
		various classes would cooperate to support this use:
		a.  walkthrough the potential use showing how each 
			user input would result in responses among the
			different classes identified earlier
		b.  when one class should communicate with another, make
			certain you have a message in the receiving class
			that can be sent by the communicating class to
			achieve the intended purpose.  If you don't add one;
		c.  document these walkthroughs with use cases, scenarios,
			interaction diagrams or message-trace diagrams.
		d.  document any assumptions or inferences not obvious 
			from the diagrams or other descriptions with 
			annotations to those diagrams or other descriptions.
		e.   check your results carefully with your potential users.
	
	Now we have completed architectural design.  With practice, you 
should become more proficient with this method.  Typically in industry,
six months to two years of practice is needed to become proficient.