The Perils of Arbitrary and False Precision

[120mm]

A fine example of false precision, and using quantitative terms where they do not apply is in the following "study":

http://www.rd.com/national-interest/...s/article.html

A recent Reader's Digest article, where they rank colleges for safety, using 19 different variables.

The problem with the study? Iowa State University of Ames, Iowa is rated as the second most unsafe campus in the US. (my alma mater, obtw) Anyone who has ever been to Ames, Iowa, will admit that something, somewhere has to be screwed up if ISU is quantified as the second least safe campus in America.

Or that the University of Worcester is like 4 from the bottom, while Boston U. is 4 from the top in safety ratings to find an "apples to apples" comparison. Anyone with a full and functional brain pan could walk around either campus and realize that Boston U. (my "other" alma mater) is probably a less safe place to be than Worcester.

Frankly, they chose largely irrelevant variables vis-a-vis safety, and then assigned them arbitrary values, which they then took very seriously in their analysis.

In other words, most of these folks are full of crap.

[Hacksaw]

Clearly we have always been inflicted with those who are apt to assign numeric values to everything from individual military performance to Corps COA Evaluation. Specifically why most people like this type of analysis is probably beyond knowing, but I offer the following as possibilities...

1. It is comforting for some (even if they know it is intellectually dishonest) to be able to point to a numeric outcome as a rationale for their decisions. [I]I think this is because they sense it provides a level of freedom from culpability, "but the numbers said this was the best COA, I shall have the offending staff officer shot!"

2. It provides a level of uniformity across the force, "If we all use the same criteria (and associated definitions), we will all come to the same conclusion." I call any reader's attention to the big CAS3 decision brief exercise that a generation of officers were forced to grind out complete with decmat and pairwise comparison.

3. We like to kid ourselves that we can, thru calculations, remove randomness, complexity, and chaos from the nature of our business. Which we all know is horse feathers....

The hardest trick I ever had with Division Commanders (planned for four) was fostering the idea that if we got everyone, metaphorically speaking, marching somewhat in the direction... that was a very good thing. And that sometimes, despite our best efforts, an action taken has unintended/unpredicted consequences. The best we can do is develop plans so that we can account/react/mitigate the effects when those occur.

I batted 50% with those four, one went on to be the hero of New Orleans, the other the hero of Mosul. A coincidence perhaps, but I think crises helps focus the mind.

Live well and row

[Ken White]

...
I batted 50% with those four, one went on to be the hero of New Orleans, the other the hero of Mosul. A coincidence perhaps, but I think crises helps focus the mind.

Of Ol' Russ is deserving of accolades.

Or many days resting and loafing in the shade...

[Jedburgh]

Edge, 15 Sep 08: The Fourth Quadrant: A Map of the Limits of Statistics

......In the following Edge original essay, Taleb continues his examination of Black Swans, the highly improbable and unpredictable events that have massive impact. He claims that those who are putting society at risk are "no true statisticians", merely people using statistics either without understanding them, or in a self-serving manner. "The current subprime crisis did wonders to help me drill my point about the limits of statistically driven claims," he says.

Taleb, looking at the cataclysmic situation facing financial institutions today, points out that "the banking system, betting against Black Swans, has lost over 1 Trillion dollars (so far), more than was ever made in the history of banking".

But, as he points out, there is also good news.

We can identify where the danger zone is located, which I call "the fourth quadrant", and show it on a map with more or less clear boundaries. A map is a useful thing because you know where you are safe and where your knowledge is questionable. So I drew for the Edge readers a tableau showing the boundaries where statistics works well and where it is questionable or unreliable. Now once you identify where the danger zone is, where your knowledge is no longer valid, you can easily make some policy rules: how to conduct yourself in that fourth quadrant; what to avoid......

[Van]

The confusion between accuracy and precision is one of my personal hot-buttons. As an example of the problem...

A guy is measuring things (doesn't really matter what) and only has tools to measure to a tenth of an increment (1.2). He starts talking about 80% of this quantity, and insists that it is exactly .96 (1.2 x .8), without realizing that this is stupid, as he can't measure to this degree of precision, where describing it as "between .9 and 1.0" makes sense and is accurate.

Another example;
A guy with a watch that is only marked 1 through 12 without hashmarks for minutes can be on time every time for appointments because his watch is accurate, gains or loses only a couple of seconds a day, and reflects the time on Naval Observatory's atomic clock, but without precision. The guy with the display down to seconds is always late because his watch loses two minutes a day, or possess greater precision by two orders of magnitude without being accurate.

But words like "about" and ending in "-ish" disturb the harmony of the Type A personalities that call the shots, so they demand a precise and wrong number rather than a less precise but accurate number.

And this is why I argued that CAS3 should include a block on statistics (and got told to sit down and shut up).

[120mm]

But words like "about" and ending in "-ish" disturb the harmony of the Type A personalities that call the shots, so they demand a precise and wrong number rather than a less precise but accurate number.

Especially the mouth-breaking jerkoffs who try to make you come up with a binding number on the spot, in a scene reminiscent of "A Few Good Men".

Dude, I just told you my timeline was completely dependent on a house of cards. How the heck do you expect me to make a time estimate that you will tie me to, later....

[Ron Humphrey]

And this is why I argued that CAS3 should include a block on statistics (and got told to sit down and shut up).

My Stats course did do a lot for me in terms of remembering to take metrics with the BIIIIIG bucket of salt they require

And I really liked your analogy considering that although the extreme precision watch is problematic it doesnt change the fact that the regular watch is still a ton better than trying to guess what time it is by looking to the sky(especially at night)

Metric use -Good
Metric abuse -bad
Metric Dependancy- Requires a lot of therapy and tons of CS(Common Sense) checks in order to be addressed

[selil]

In my area we deal with accuracy versus reliability especially with assessments. Lots of pictures of arrows on targets which I really understand.