Bad Logic

How dangerous are fireworks?

2005-07-02T05:36:00.000-07:00

Every Fourth of July you'll see articles telling you how dangerous fireworks are. For example, here is the 2005 press release from the U.S. Consumer product Safety commission on fireworks. The CPSC estimates that there were "9,600 emergency room-treated injuries associated with fireworks in 2004."

Note the following:

They give an estimate without any mention of how they came up with the estimate, or even error bars.
They do not give an estimate of how many people used fireworks without requiring emergency room visits.

In other words, they aren't telling you know what the risks are. They're just trying to scare you.
Of course, this doesn't mean that fireworks are safe. Just that the CPSC doesn't think you can think.

More Scary then Bad

2005-06-04T09:42:00.000-07:00

The logic in this example is more scary then bad. Local public schools in Illinois are funded, strangely enough, by local taxes. Specifically, most are funded with local property taxes. This does lead to a problem --- rich communities give their schools more money then poor communities.

Every now and then someone tries to shift the funding to the state level. Of course, income taxes would have to rise to cover this. The proposers always assure us that property taxes would fall as a result. The only reason for all of this is the children (of course).

Here is another reason from a Wednesday Journal article:

Alheim added that taking the burden off local property taxes would lessen the "sense of control" taxpaying parents would have regarding school operations, and return it to "the educators' hands."

Got that? You're paying for it, but if it goes through Springfield it really isn't your money anymore...

Lies, Damned Lies, and Statistics

2005-06-03T18:28:00.000-07:00

If you want information about hiking on the Grand Canyon's read the warning first:

A surprising majority of victims rescued from Grand Canyon are young, healthy males between the ages of 18 and 40 attempting to hike to the river and back in one day.

They're trying to do a good thing and let young healthy guys know that the Grand Canyon isn't a safe place. It's a wilderness, and if you screw up badly enough, you die.

But without knowing what the demographics are for people trying to hike to the river and back in one day, the above statement is meaningless. Leaving it vague isn't a good sign either. If 99% of the people hiking into the Canyon are between 18 and 40 it shouldn't be surprising that the majority of victims rescued are between 18 and 40.

What matters more then how

2005-05-21T18:38:00.000-07:00

On May 3rd 2005, the Chicago Tribune published a story describing a draftsman who had been stamping architectural drawings with a dead accountant's stamp. For those of you unfamiliar with architecture, in most places you must have an architect stamp construction drawings before you do the construction.

The architect assumes legal responsibility for the design when they are stamped. Of course, not any one can be an architect --- you have to be professionally certified.

When state officials found out that someone without a license had been stamping drawings they were concerned about the building's structural integrity. But it turns out that the buildings were sound.

Susan Hofer, spokeswoman for the Illinois Department of Professional Regulation said, "The plans themselves were structurally sound because they had been done by a real architect."

No.

The plans where structurally sound because if built, they would not fall down the next time it rained, they could handle snow loads expected in Chicago, and they wouldn't collapse if someone slammed the door real hard. Their structural soundness is a property utterly independent of who drew them, or how they were designed. What matters more then how.

If a competent draftsman can produce structurally sound plans, it makes you wonder why architects have to be licensed...