Forest StatBadExamples

For example, reports that alcohol sales are soaring, because sales increased by 5% between 1999 and 2004.

Based on a study conducted in a public school it was found out that that 75% of delinquent students are Asian.

What would you think about that statistical report without the knowing the raw data? Majority of the Asian students are delinquent right?

Here is the raw data/information: Total student populations: 1,000 where 800 are Asian descend (Either both parent or just one is Asian) 200 are mixed (American/Hispanic) reported Delinquent Students: only 4 of which 3 are Asian descend

It's easy to be fooled by statistics if you're just given the final figure without background of the raw data, your populations, and other pertinent information to make the presentation more objective.

Scenario: Driving home late last night. Listening to NPR when I could find it. Heard a commentator say something to the effect of, “No Democratic president has ever won office without carrying the state of Missouri.” Sudden urge to rip the radio from the dash and never listen to any newscast again.

I just searched for “without winning Missouri” on Google.com. You don’t have to be smart to search nowadays – all you have to do is enter the key snippet. Lots of results, most saying effectively the same thing: “Wow! How did Obama win without Missouri?” Apparently, a Democrat being elected president has always coincided with Missouri’s going Democratic (but not the other way around – Missouri has predicted a Democrat and been wrong, as several sites bemoan). Whoopee! A way to predict the winner! If a Democrat won then Missouri must have gone Democrat. But this time, it failed.

Failed indeed. This is a fine example of pure statistical hype. Good stats classes teach ways to avoid this kind of math mistake. Missouri was never a validated predictor of the Democratic wins, and the so-called “American opinion.” “What? It aligns so perfectly. How can you say that?” Even if the next 10 Democrats carry Missouri and win the presidency, it is still an invalid predictor in my book. I can’t even muster a reasonable case for real covariance. This was just the same bad math that has sportscasters saying:

“Well Tom… following a line-drive single, this batter has never hit the second pitch from a left-handed pitcher on a Tuesday night in the third inning”

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Forest_Error_Analysis_for_the_Physical_Sciences

“Well Tom… following a line-drive single, this batter has never hit the second pitch from a left-handed pitcher on a Tuesday night in the third inning”