I am wondering id the following diagram reflects the actual interconnection between instructional systems technology and Human-Computer Interaction design from practical viewpoint?
If intersection means what is common in (shared by) the two sets expressed by the Venn-diagram, then it is not contextual design. I think HCI is a relative complement of IST, and context management complements both.
Following on from Imre, I see now that one circle is a technology circle, and the other is a design circle, so their intersection must perforce be to do with technology design or design of technology. Is this your viewpoint, Zuheir?