The Opposition and further experiments

[From Dick Robertson,990511.1555CDT]

Bill Powers wrote:

[From Bill Powers (990510.1146 MDT)]

Dick Robertson,990510.1221CDT--

>What I want to ask is whether this matching law says, and
>has confirmation for, subjects (people or animals) choosing alternative
>for getting payoffs in proportion to the relative proportions of the payoff,
>instead of simply devoting all their efforts to the option that has the best
>payoff? I don't undersatnd why it is so hard for me to get an answer to this
>question. It seems a simple one to me. What am I missing?

Yes, as I understand it that is the claim: the choice is supposedly
proportional to the payoff (sort of). You have to understand, however, that
the payoff is VERY SMALL, so the animal may well have reason to continue
searching for a better payoff by trying other keys. Pressing the key with
the higher payoff exclusively would still not produce subsistence-level
food intake. I suspect that with much higher payoffs, animals would tend
much more to pick the best key and ignore the other one. But that's just my

Well, it took a good bit of effort, on several response options, but I got a
payoff (more than ) matching the (r1->rn). As in Powers (990510.1146)

Apparent matching _could_ be explained by saying that animals basically
select the best key and use it, but as the total payoff declines, they
begin more and more often trying the other key. Actually, with concurrent
schedules I think that there is always a net gain from trying the other key
(this just occurred to me). An occasional press on the less productive key
does not substantially reduce the delivery rate from pressing the best key.

Now that makes so much sense that I wonder why I didn't think of it myself. But
that's why I ask questions, because I often don't think of it myself. But this
and the further speculations Bill gives in this post suggests two lines in
investigation. One, to try further experiments to check out whether this is a
real (and more than trivial ) phenomenon. The other to make the further detailed
analyses that Bill does so marvelously--like that old study of the rat experiment
where your detailed analysis finally revealed that the so-called phenomenon was
actually an artifact of the experimental apparatus. That fact had been obscured
to casual observation because of the intricacy of the experimental set-up.

This means that pressing the best key exclusively is NEVER the best
strategy, under the schedules as defined. The animal should peck one key
for a short time, and if that doesn't produce a bit of food immediately, it
should peck the other key for a short time, and so on back and forth as
quickly as possible. This will produce what looks like a tendency to
matching, because the animal will give up on the less productive key
without receiving a reward sooner than on the more productive one.

This too makes a lot of sense to me. It might also account for the gambling
results that Brue Gregory mentioned.

I had begun thinking of an experiment that I might run with my 4 6-9 year old
computer-game-playing gransons, and maybe some neighbor kids too. I'ts been so
long since I did any programming that I'm not sure how well I could do it. But I
would appreciate you experts glancing over this initial idea for any obvious
defects or omissions.

                OBJECTIVE to test whether Ss exposed to multiple alternative
structures for controlling a CV with different rates of payoff will divide their
use of options in proportion to the different payoff rates.

SET-UP INSTRUCTIONS "This is just part of a computer game like Command and
Conquer." In this one you want to get an many tanks (=df payoff options) as you
can, as fast as you can. You can get them from (e.g. ) one or more of these
three different sites.

Ss: Computer-game-playing kids.

I think such Ss are preferable to pigeons or rats in that you can ask them
questons like:
How does it work? What were you trying to do? Were some sites better than
What works best to win? Etc. The answers to questions like that might suggest
modifcations that would employ The Test.

Conditions: 1) The Ss are not told that different options payoff at different
rates. They learn that from their experience.
2) The task has to go on long enough to learn (1).
3) Instructions must be carefully phrased to not suggest any hints that the Ss
could take as telling them what E wants them to do.

1) Option A paysoff 1 tank(whaever) every 10 sec; Option B, every 20-sec; Option
C every 30-sec.
2) Option n resets as soon as it paysoff.
3) Game goes on until S exits.

4) Program calculates # clicks per payoff, by site (option); total number of
payoff runs; total # clicks; ra/(ra+rb+rc); Pa/(Pa+Pb+Pc), etc.

Any help appreciated.
Best, Dick R.