Aggregate Data (was Re: Bizarro PCT)

[From Rick Marken (990826.0900)]

Bruce Gregory (990825.1006 EDT)

The stock market is a rich source of aggregate data.

As is the economy as a whole. I think science can be based
on aggregate data when that data is extremely well behaved,
as it is with the aggregates of electrons that you mentioned,
the behavior of which can be described precisely and reliably
by an algebraic equation (I = VR) and as it is with aggregates
of goods and services, the behavior of which can be described
precisely and reliably by simple differential equations (like
those presented in _Leakage_, T. C. Powers, Benchmark
Publications, http://www.benchpress.com/Leakage1.htm).

Aggregate data are still irrelevant to individuals; Ohm's
law doesn't describe the behavior of any individual electron
and the marcoeconomic laws don't describe the behavior of
any particular goods and services in the economy. But I
think it is often worthwhile to understand the aggregate
phenomenon itself. It's obviously useful to know Ohm's
law; and I think it's useful to know that economic growth
depends on leakage of purchasing power from the macro
economy, not on capital investment (which is a constant
in the macro economy).

Aggregate psychological data (such as that collected by
researchers like C&S) is, therefore, not useless _in
principle_. It could tell us something about the behavior
of _groups_ of people. The problem, from a PCT perspective,
is that this kind of data is irrelevant because PCT is
a model of _individuals_. PCT can explain the behavior
of _groups_ of individuals (as we will see when the CROWD
modeling discussion begins). So there is aggregate data
that _could_ be handled by PCT. But the aggregate data
collected in conventional psychology is just not good
enough (very high "error" variance) for this kind of
exercise. The problem is that, if you successfully build
a model of a group of control systems that replicates
the aggregate results found in study X, you are likely to
find, upon repeating study X, that the aggregate results
are completely different. Unlike Ohm's "aggregate" law of
electron flow, where it's _always_ true that I = VR, the
"aggregate laws of behavior" found in conventional psychology
experiments are more like "I is generally near VR, plus or
minus a few amps".

Norman Hovda (990825.16:06 MST) --

based on my observations and using my dynamic data distribution
(DDD) model to measure _one_ stock's price data will yield
similar perceptual control system phenomenon as demonstrated by
aggregate data derived from the entire stock market index data

This sounds interesting. What are the perceptual control system
phenomena that are demonstrated in the behavior of the aggregate
and individual stock prices?

Best

Rick

···

--
Richard S. Marken Phone or Fax: 310 474-0313
Life Learning Associates mailto: rmarken@earthlink.net
http://home.earthlink.net/~rmarken

[From Rick Marken (990826.0920)]

Two little points on my previous post [Rick Marken (990826.0900)]:

1. I hope Bruce Gregory understands that I was agreeing with
him [Bruce Gregory (990825.1006 EDT)].

and

2. I know that Ohm's law is I = V/R not I = VR. My use of the
latter equation in my post was a result of posting in too much
haste.

Best

Rick

···

--
Richard S. Marken Phone or Fax: 310 474-0313
Life Learning Associates mailto: rmarken@earthlink.net
http://home.earthlink.net/~rmarken