sequence versus program

CSGnet Archive CSG1995
1

[From Bruce Abbott (951114.1210 EST)]

Bill Powers (951114.1032 MST) --

First Shannon Williams responds to a post that would not be _sent_ until the
next day, now Bill sends a post he will not _write_ until the next day (I
received it on the 13th)! Are we caught up in some kind of temporal anomaly
here?

Sequences are involved in both cases, but when a program is involved,
_which_ sequence is followed by which other sequence depends on
unpredictable data from outside the program (unpredictable by the
program). Does this make my distinction clearer?

I wish I could say "yes." If the delay is unimportant then it should not
matter how the delay is accomplished, whether via a program loop that counts
down to zero, a mechanical timer, or a delay line. What matters is that the
event, "time delay up" always produces the same transition to the same next
state. Yet earlier you suggested that, because a state-transition was being
initiated by the passage of a specified time, the state diagram represented
a program rather than a sequence. Have you changed your mind?

I would suggest that both of the mechanisms I described produce a sequence
or linear chain, although their organization is different. On the one hand
you have:

        1------>2------>3------>4
                > > >
                V V V
               bang bang bang

In the other you have:

        1------>bang------>2------>bang------>3------>bang

The first represents a centrally-ordered sequence that procedes whether or
not the caps actually fire; the second represents a different sort of
mechanism that depends on the success of each action in bringing about a
particular perceptual result, and will immediately stop if a cap fails to fire.

Are you now saying that both are sequence-level and not program-level
systems, according to your definition?

Regards,

Bruce

2

<[Bill Leach 951114.20:49 U.S. Eastern Time Zone]

[Bruce Abbott (951114.1210 EST)]

I might suggest that the point of view makes a difference here.

In both of your examples, there is a decision point and the difference
between them is only what the decision is based upon. In a continous
system, "waiting" is an active event.

I think that sequence is difficult to think of in terms of control of
perception and it is one of those "level problem" areas.

Sequencing is, I think, a relative matter. That is we develop a sense of
sequence based upon the "one before the other" or "one after the other"
without (much?) regard for the elapsed time.

Thus, I tend to think that "sequence" is not "A" followed 2 seconds later
by "B" but rather ONLY that "B" follows "A". The elapsed time itself is
probably not a part of the sequence.

In any event, it seems that if one is trying to control perception that
is a sequence, it would only be necessary that one event follows the
other without regard for time seperation.

-bill