Friday, November 17, 2006

An Example of Discovery-Based Learning

Read the first sentence--the first freakin' sentence--of this article, and see what's wrong. There's no math there. The answer given--is the wrong freakin' answer. Perhaps the reporter misinterpreted the problem, but as it's written, it's wrong wrong wrong. There is a correct answer here, and 40% isn't it. In fact, several minutes of instruction in combinatorics would give an answer well under half of what was reported.

Ugh! This was such a great book, and I read it back in the 80s. Sad that it's still so true.


Robert said...

I've always found it troubling that although journalists need a solid command of quantitative thinking in order to do their jobs today -- moreso than a lot of other professions -- the people who usually end up majoring in journalism are the ones who are looking precisely to get away from "hard" courses like math.

Conversely, we had an alumnus who was a big-wig in the newspaper industry tell our department once that a journalism major who had just a couple of courses in statistics would be able to write her/his own ticket with any news outlet out there, period.

Anonymous said...

How is 2/5 not equal to 40%?

Tyler said...

It's a pretty simple problem. It's just (4/52)x(3/51)=(12/2652)=0.45%, (2/5) of 40%. Ya, I'm a geek, I know.

Tyler said...

Oh, I read the problem wrong. I was doing probability of finding two jacks when you only flipped two cards. It's a little more complicated. It involves permutations I think. It's interesting that this very poorly-written article's author's name is James Joyce III. Perhaps the grandson of the famous writer, James Joyce?

allen said...

According to

jour-nal-ist [jur-nl-ist] -noun
1. a person who practices the occupation or profession of journalism.
2. a person who keeps a journal, diary, or other record of daily events.

My definition is that a journalist is the opposite of a specialist, i.e. someone who knows less and less about more and more until they no nothing about everything. Before the rise of advocacy journalism a disciplining effect came from the demands of journalistic ethics - to avoid the appearence of parisanship you had to check your facts - but those days are gone. Displaying a certain craftiness in the support of a favored agenda carries a higher approval rating then mere, factual accuracy.

rightwingprof said...


There's a whole generation of lottery ticket buyers, right there.

Darren said...

Tyler, I don't get it. 2/5 of 40% is 16%, not .45%. What did you mean?

rightwingprof said...

Wow, Trachtenberg is still in print. I had this back in the 60s when I was in school (my math teacher grandfather got it for me).

Btw, it's a great system, but not a substitute for basic math skills.

Tyler said...

I meant to say "or". I meant 2/5 OR 40%.

Anonymous said...

As a thought . . . given the age of the kids, the actual problem MAY have been based on a 5-card deck, and the problem may have been as simple as 'what are the odds of having two jacks after we've flipped all five of the cards' -- in which case the math would be correct, the reporter would be derelict in reporting the details given him by the teacher, STILL making him incompetent, and the lesson would be inane. A slightly harder question would be what would the probability of the first two cards being turned over being jacks (given the 5 card deck premise) would be 2/5 * 1/4, or 10%.

Given the difficulty level of the problem as stated, I would bet my deduction is correct.

As a side note . . .Spot the mathematical error in the song "5 to 1" by The Doors.


Darren said...