[Martin Taylor 920323 16:30]
(Rick Marken 920323 8:30)
Rick, I think your posting on the moth and the larger question of behaviour
and open loops brings us close to agreement. There COULD be open loop
behaviours in which the loop is closed by evolution, but it seems unlikely
that such "behaviours" would survive a long evolutionary path, because
circumstances DO change, and actions that are effective in one situation
could be deadly in another.
But, in the field of HCI, we see numerous situations in which the interface
designer has precluded the closing of the loop, at least forced it to a higher
level. The user imagines the state of the computer, and issues a command
intended to affect that imagined state. The designer may not have provided
any way for the user to determine either the new state or the effect of the
command as a state difference, unless the initial state is sufficiently wrongly
imagined that the command is a "syntax error." I think one of the main
benefits of direct manipulation interfaces is that they provide continuous
possibilities for the loop to be closed. The user can see all the time
how the actions are affecting the perceived state of the machine. This
aspect of the benefits of direct manipulation is never (I think) discussed.
Instead, the idea is put about that such interfaces eliminate the possibility
of error, which they don't.
This may be my last posting from this address. Gary has moved my reception
of the CSG-L postings to another machine, at my request. I will henceforth
be found at mmt@ben.dciem.dnd.ca
Martin