Comments on: 1,400 Rectangles

By: Lorraine Baron

Lorraine Baron — Sat, 03 Nov 2012 16:00:48 +0000

Hi Dan:
I stuck with Marc – because I love Marc and I am loyal. (…and he may still right in some parts of the world!) :)

However, in my mind and in my gut, I expected that most North American responders would select the SCREEN SIZE they watch…

What is the average screen size of tablets and tvs?… that is the same…. I will bet!
Lorraine ;)

Lorraine Baron
UBC
Napa Valley of the North
Kelowna, BC
wine country!
http://www.hellobc.com/kelowna.aspx

By: Randy Blackwood

Randy Blackwood — Thu, 01 Nov 2012 17:46:35 +0000

I think the idea of crowdsourcing is a misconceived idea of the Central Limit Theorem developed by Laplace, which is used in statistics and indicates that if you take a large enough sample even if the sample is from data that is skewed, the sampling distribution of the means will be normally distributed and centered at the mean. But this requires the distribution to be a random sample of “factual” information. So this would be true if we were doing something like taking a random sample of the height of adults. But when you start to put their opinions in place, I don’t think you can get correct answers from “bad” information. I may not be making this completely clear, but here is a simple example that you can try with a class. Tell kids to randomly choose one number from a group of numbers that you are going to flash up on a projector, overhead, etc. Put the numbers 1 2 3 4 up on the board.
If they truly randomly picked there should be a fairly even distribution of the numbers so the average of all the numbers should be 2.5 BUT since people are not random number generators, they have a tendency to predominantly pick #3. From the book “Statistics Modeling the World” they indicate about 75% of people will pick 3, about 20% are split between 2 and 4 and only about 5% will pick 1. I have done this in class and have gotten similar results. I’m not sure this completely debunks crowdsourcing, but it does indicate that our minds can have a bias on what type of answers we arrive at.

By: Carl Malartre

Carl Malartre — Thu, 01 Nov 2012 11:34:09 +0000

I can’t answer these questions:

Are the rectangles aspect ratio influenced more by motricity (using a trackpad or a mouse, clicking and dragging) or by the idea of what a rectangle is? Is it different online than on paper?

By: Jim Doherty

Jim Doherty — Tue, 30 Oct 2012 18:07:26 +0000

Thanks Michael!

By: Michael P

Michael P — Tue, 30 Oct 2012 15:24:36 +0000

Jim, you're probably talking about this.

By: Jim Doherty

Jim Doherty — Tue, 30 Oct 2012 15:13:30 +0000

Dan

What I vaguely remember is a story about people at a carnival guessing at the weight of an elephant. Individual guesses were terrible but the aggregate guess was surprisingly accurate. Am I making up this memory? Can anyone out there verify or discredit this? As far as this experiment, I worry about the number of people who have openly admitted (claimed?) to have intentionally disrupted its intent.

All that being said, I am suspicious of the theory that a crowdsourced bunch of guesses should be reasonably accurate.

By: Dan Meyer

Dan Meyer — Tue, 30 Oct 2012 14:02:09 +0000

As far as I know, the crowdsourcing accuracy theory is largely bunk. I tried to test that theory here. Maybe Marc Garneau, who took the other side of the bet, knows.

By: Jim Doherty

Jim Doherty — Tue, 30 Oct 2012 13:05:15 +0000

Dan
Can you remind me (us?) where this sort of crowdsourcing accuracy theory comes from? I know that this is something I have read on in the past but my brain cannot find an accurate reference. I know that there is a theory that if you ask a large enough sample of people to estimate something, say the population of Fargo, ND then the average guess will be fairly accurate.

By: Dan Anderson

Dan Anderson — Mon, 29 Oct 2012 15:21:05 +0000

Huh? My scatterplot only takes a look at large_dimension / small_dimension. A 0.618 grouping would be impossible.
That said, a scatter plot certainly isn’t proof. I’d say that the data shows a very slight preference for the ratio 1.6.

By: Dan Meyer

Dan Meyer — Mon, 29 Oct 2012 14:56:21 +0000

Yeah, but like I said above any analysis that takes small / big needs to account for a grouping around 1.618 and .618.