Vera,
I'm not sure what stimulated this question, I've been distracted of late
and have lost track of some of the discussions here.
Basically, agent-based programming utilizes *delegation* (as opposed to
direct-manipulation) as a control mechanism in programming. Alex Repenning
provided a nice explanation of the distinction in:
Repenning, A. (1994). Programming substrates to create interactive
learning environments. _Interative Learning Environments_, 4, 45-74.
---Tim