[From Fred Nickols (2003.07.20.0925 EDT)] --
I like the idea of providing ways and means for people to assess their own
grasp of PCT and additional ways and means of improving said grasp of
PCT. Rick's questions are a start. If we get serious about this, I would
make one suggestion right away: There should be several forms of any
"test." One can be used as an initial assessment, a diagnostic if you
will. The results from this can point the test taker to the material from
which they might remedy any knowledge gaps. Other forms of the test or
assessment can be used to determine how well any knowledge deficiency might
have been remedied.
Another assessment issue will tie to the difference between assessing
knowledge and assessing skill or competency. The assessment instrument
might ask questions and the answers (in a multiple-choice, constructed
response or essay format) will suffice. The assessment instrument might
also present certain tasks (e.g., build a spreadsheet or Vensim or other
kind of dynamic model of some behavioral phenomenon). And, of course, the
assessment items themselves can call forth quite a bit of creativity and
imagination on the part of the test taker (e.g., one long essay item could
consist of writing rebuttals to selected criticisms of PCT).
By the way, Rick's first question intrigued me so, without benefit of
referring to any "open book" (or closed ones that I know of), here's my
response:
Q. What is a controlled variable?
A. A controlled variable can be just about anything. The term refers
to some perceived or at least perceivable aspect of our world that we wish
to control. In the course of driving to work, to draw on an often-used
example, keeping my car in whatever lane I've selected is one example of a
controlled variable, a variable that might be better named "position of
auto with respect to lane." The speed at which I'm traveling offers
another example of a controlled variable. Both of those examples are at
what many people might call the "conscious" level. There are controlled
variables of which I am not ordinarily so consciously aware. My heartbeat
and respiration rates are controlled variables but I am not aware of
controlling them and don't believe I can consciously do so (although I am
told that Yoga masters can, within limits, control both). For a more down
to earth example, I just took a sip of coffee from the mug on my
desk. That involved grasping the cup, raising it to my lips, opening my
mouth, touching it to my lips, tilting it, taking a swallow of now lukewarm
coffee and then tiling it back the other way, closing my lip and returning
the mug to its previous position on my desk. There are many "controlled
variables" in that simple act; consider just a few: the position of my
fingers in the handle of the mug, the position of the mug with respect to
my lips, the angle and rate of the tilt (up and down), and the position of
the mug on the desk upon its return. I did not think consciously about
controlling these things, I simply took a sip of coffee. Controlled
variables can also be much "bigger" as it were than taking a sip of coffee
or driving to work. As a manager or executive, I might be bent on
controlling some aspect of the performance of my organization (e.g., sales,
profit, expenses, productivity, quality, unit costs, etc.). Unlike taking
a sip of coffee or driving to work, these controlled variables are not
under my direct control; that is, my behavior does not affect them
directly. To control variables such as those just mentioned, my actions
must be viewed as interventions in some larger structure. I cannot change
expenses directly, but I can hire (or fire) people in a pretty direct
manner and, as a consequence, affect expenses. I can direct that cheaper
materials be substituted for those now used and thus affect expenses. I
can direct that prices be lowered (and hope that sales will increase). In
short, when I seek to control variables that are far removed from me in
space and time, I need a map of the architecture in which those variables
are embedded. Why? Because in order to reliably control those distant
variables, I need to know the intervening variables that must also be
controlled. Change, in the case of sipping coffee or driving to work, is
pretty direct; I grasp the cup, turn the wheel, apply the brakes, take a
sip, accelerate and slow down and put down the cup (as a matter of fact, I
can be spotted on occasion driving and drinking coffee at the same
time). But, change in controlled variables like sales and expenses is
indirect; I act in one place at one time and I intend to realize certain
effects elsewhere later on.
The preceding is a reasonable reflection of my current grasp of the meaning
of the term "controlled variable." Having written it out, it prompts some
questions of my own. Is a controlled variable anything we attempt or
intend to control or is it only those things we can in fact control? Is
there a point where disturbances are so overwhelming that any pretension at
control of a particular variable is impractical (e.g., when product
failures drive expenses through the roof, or someone jostles my elbow and
the mug winds up in a position that spills hot coffee in my lap or when
another car veers into my lane forcing me out of mine) or, do these kinds
of disturbances mean merely that I have altered my reference level for the
controlled variable in question? I guess what I'm asking is does a
controlled variable depend on the existence of control or intent to control
enough to define it as such?
Good question, Rick.
Regards,
Fred Nickols
"Assistance at a Distance"
Distance Consulting
nickols@safe-t.net
www.nickols.us