To summarize, Dr. Jones collaborates with the programmer in diagramming a program and its design alternatives.
	It maintains the focus set of program elements throughout a design dialogue with the programmer.
	The focus set contains only the relevant elements at each step, so the diagrams stay simple.
	These focus sets can be kept in a history so that the programmer can revisit previous steps and branch to explore alternatives.
	This could be an opportunity for design rationale capture, although that’s not what I’m focusing on in this thesis.