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Discussion Starter · #1 ·
I was reading this article on how people misunderstand rain forecasts. I find it quite unbelievable.

http://news.yahoo.com/s/livescience/20090420/sc_livescience/rainyweatherforecastsmisunderstoodbymany

If, for example, a forecast calls for a 20 percent chance of rain, many people think it means that it will rain over 20 percent of the area covered by the forecast. Others think it will rain for 20 percent of the time, said Susan Joslyn, a cognitive psychologist at the University of Washington who conducted the study.
Many people? Give me a break. Who is dumb enough to think either of these things? Only 20% of the area? Only 20% of the time? Does the word CHANCE mean anything? If I say you have a 20% chance of winning at a casino slot machine, do you think that means you will win at 20% of the casinos in the area?

The reality: "When a forecast says there is a 20 percent chance of rain tomorrow it actually means it will rain on 20 percent of the days with exactly the same atmospheric conditions," Joslyn explained.
Uh...what? Does that make sense to anyone? What the hell does that mean? Talk about taking a simple concept and making it totally confusing.

Put another way, on that day there's an 80 percent chance there will be no rain anywhere in the forecast area.
Yeah, okay. Now we are making sense. Why didn't she just say that in the first place?

Is this stuff really so hard?
 

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had it in the ear before
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50% chance of rain in Florida pretty much everyday, and u get to flirt w/ the hawt traffic lady, sign me up for that job!

Jennifer Epstein
 

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still shedding season
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mohair_chair said:
Talk about taking a simple concept and making it totally confusing.
See: Cognitive Psychologist

George Carlin said something like "Think about how stupid the average person is. Then think about the fact that half the people are dumber than that."
 

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Festina Lente'
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Hmm... 30% chance of rain through Big Sur during my ride back from Coops. If I only ride 70% of the time, do I get rained on?
 

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2 busy workin' 2 hang out
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People are absolute dumbasses much of the time. The human race just piggybacks on the brighter members to further itself.
 

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kykr13 said:
See: Cognitive Psychologist

George Carlin said something like "Think about how stupid the average person is. Then think about the fact that half the people are dumber than that."
Ummmm...that would be the median, not the average. So much for how dumb people are...
 

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mohair_chair said:
Quote:
<TABLE cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2 style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset">The reality: "When a forecast says there is a 20 percent chance of rain tomorrow it actually means it will rain on 20 percent of the days with exactly the same atmospheric conditions," Joslyn explained. </TD></TR></TBODY></TABLE>
Uh...what? Does that make sense to anyone? What the hell does that mean? Talk about taking a simple concept and making it totally confusing.
What is confusing about this? Just as when you flip a coin, you are saying under exactly the same conditions there is a 50% chance of heads coming up. Under the exact conditions there is a 20 percent chance of rain. Under the exact conditions there is a 12% chance of a carbon fiber bike shattering into a million pieces. These percentages are not random numbers assigned to any coin toss, any carbon fiber bike any weather day. They are only the chances under specific conditions. So, for conditions of a certain humidity, wind, temperature etc, on one out of 5 of those days there will be rain, on 4 out 5 of those days no rain. A dry day cannot be compared to a humid day, a carbon fiber bike that has never been ridden cannot be compared to one that has just run into a brick wall at 200 MPH.

What is it about the statement do you find confusing?

I do agree about the lack of understanding about statistics.
 

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lancezneighbor said:
I do agree about the lack of understanding about statistics.
Relatively few people know what a statistic is -- a value such as an average derived from a sample of a population. as an example, batting average for a baseball player in a particular year is not a statistic because it accounts for all the at bats...it is not from a sample.
 

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Gruntled
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They say we only use 15% of our brains. Whenever I hear that, I wonder what the other 65% is for?
 

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Climbs like a sprinter...
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The reality: "When a forecast says there is a 20 percent chance of rain tomorrow it actually means it will rain on 20 percent of the days with exactly the same atmospheric conditions," Joslyn explained.
Uh...what? Does that make sense to anyone? What the hell does that mean? Talk about taking a simple concept and making it totally confusing.
It means that if you took 100 days that had the exact same atmospheric conditions it would rain on 20 of them.
 

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Discussion Starter · #12 ·
What is confusing is that that is not what "20 percent chance of rain tomorrow" means. When you specify "tomorrow," you are talking about a specific day. To then add "it will rain on 20 percent of the days with exactly the same atmospheric conditions" means we aren't talking about tomorrow anymore. We went from tomorrow to some nebulous series of dates.

Plus, no one except her would ever explain it like that. I can't think of a more cryptic explanation for something so simple. The fact that the article then has to explain what she said confirms that it is confusing.
 

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Jim Nazium said:
They say we only use 15% of our brains. Whenever I hear that, I wonder what the other 65% is for?
i think some use even less.... :)
 

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Discussion Starter · #14 ·
bmxhacksaw said:
It means that if you took 100 days that had the exact same atmospheric conditions it would rain on 20 of them.
So how does that help explain that there is a 20% chance of rain TOMORROW?
 

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mohair_chair said:
So how does that help explain that there is a 20% chance of rain TOMORROW?

think outside the Bun...
 

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Climbs like a sprinter...
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mohair_chair said:
So how does that help explain that there is a 20% chance of rain TOMORROW?
That's why it is called a chance. If the atmospheric conditions on that day indicate that it would only rain on 20 out of 100 with the same conditions then there is a good (80%) "chance" that it won't rain tomorrow.
 

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catzilla said:
Yeah! I agree completely! Everyone but me is either an idiot or an elitist!

Exclamation points!!!!!!!!

see....cat is thinking outside the Bun...
 

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What it really means is:

Forecaster: "I don't think it will really rain, but it might, so if it does, I told you so" Just a fancy way of CYA.
 
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