Hacker Newsnew | past | comments | ask | show | jobs | submit | elephant_burger's commentslogin

These are the three questions of the Cognitive Reflection Test:

(1) A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball. How much does the ball cost? __ cents

(2) If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets? __ minutes

(3) In a lake, there is a patch of lily pads. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half of the lake? __ days


Here's another question for the Cognitive Reflection Test:

In a study of 3,428 university students, 50% of participants across Harvard, MIT and Princeton got a question wrong on a Cognitive Reflection Test. What percentage of MIT students got the question wrong?


What is the answer?


Think its meant to be tongue in cheek. Read the OP link, and you'll see where it came from.


You cannot answer from the data in the question ;)


Here's ChatGPT's responses. It's fascinating that it provides the same incorrect answers as people... I'm not sure how to interpret this from the robot.

(1) "The ball costs $0.10. The bat costs $1.00 more than the ball, so it costs $1.00 + $0.10 = $1.10 in total."

(2) "If 5 machines can make 5 widgets in 5 minutes, then each machine can make 1 widget in 5 minutes / 5 machines = 1 minute. Therefore, 100 machines can make 100 widgets in 100 minutes."

(3) "If it takes 48 days for the patch of lily pads to cover the entire lake and the patch doubles in size every day, it would take half that time, or 24 days, for the patch to cover half of the lake."


Great article. I’ve tried prompts to remind myself “don’t get angry” but tbh it hasn’t helped. Instead I’ll try remind myself “don’t feel attacked” and ask for some time to think


I can't speak more highly of Ryan Singer's work on Shape Up. It has transformed how we approach work by inverting the question from "how long something is going to take" to "how long do we want to spend on this".


Does this contradict the view that the Black Death started in rats in Europe?


I don’t think that was ever a supported view. When I was in high school decades ago the view, even then, was that it came from somewhere in Asia, probably China.

They knew with a high degree of certainty the plague spread along the Silk Road carried by blood feeding parasites on rats. They had timelines of outbreaks well documented, but they didn’t know where it first infected humans.


iiuc that hasn't been the majority scientific view for at least the last 5 years


Thank you for sharing. This is the first chapter from Todd Rose's excellent book The End of Average. In the book, he also touches on the fascinating topic of context. For example there is no such thing as a person's average level of aggression - IF I am around my parents I tend to get aggressive, but IF I am around friends and strangers I am calm.

https://www.penguin.com.au/books/the-end-of-average-97801419...


FWIW the face of the statue of the "the typical woman 'Norma'" at https://www.thestar.com/news/insight/2016/01/16/when-us-air-...

resembles Dana Scully of The X-Files.

I also enjoyed Todd Rose's book, which examines the history of (mis-)interpretations and (mis-)uses of the "average":

The End of Average

https://www.amazon.com/End-Average-Unlocking-Potential-Embra...


Even Rose's article (I haven't read his book yet so I can't really say about that) tiptoes around what was going on here. It wasn't just a naive application of statistics. Rose gets through the Norma story without mentioning eugenics once, but the whole episode is so obviously part of America's pre-WWII eugenics swoon. Beyond specific beliefs about politics, race or genetics, but linked to them, there was a whole Zeitgeist, the collectivist spirit of the age that gave us Busby Berkeley musical numbers https://www.youtube.com/watch?v=ysvQ5MaUbd8 and the IBM company songbook https://www.networkworld.com/article/2333702/a-history-of-si... . This was a time when it was acceptable, indeed it was progressive, to be violently hostile to difference or defectiveness: see for example War Against the Weak https://waragainsttheweak.com/ and, maybe most especially, The Black Stork https://global.oup.com/academic/product/the-black-stork-9780... . And of course it's no coincidence that the pioneers of statistics tended to be particular fans of eugenics themselves.

(I am not an expert on anything.)


Looking at deaths globally by age as a distribution shows how the average can mislead https://www.google.com/search?q=deaths+globally+by+age&rlz=1...


To your point, the global “average” life expectancy since the 1700s to today visualized https://ourworldindata.org/grapher/life-expectancy?tab=chart...


How to mislead with data 101!


Indeed, though see the article linked at the bottom of that one, which goes into more of the nuance and has distribution curves etc: https://ourworldindata.org/life-expectancy-how-is-it-calcula...


Do you think YouTube ad revenues could exceed Google Search? $15bn YT vs $98bn Search (2019)


Today, you are likely more valuable to YouTube watching ads. In the latest earnings call Alphabet CFO made the comment:

"both YouTube Music Premium and YouTube TV do have higher content acquisition costs as a percentage of revenues than YouTube ads and we are early there continuing to build out that subscriber base."

YouTube still pays out the majority of subscription revenue to publishers based on viewership but likely must also pay out more to music creators and labels. This is also not counting the costs of its original content.

Q32020 Alphabet CFO earnings transcript https://www.fool.com/earnings/call-transcripts/2020/10/30/al...


Google acquired YouTube for US$1.6bn in 2006. How much is it worth today?


Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: