Tuesday, August 31, 2010

I learned something new!

I'd always wondered how they do the crowd-estimate thing in the news, and thanks to a piece at AOL News, now I know:
[T]he "Jacobs Crowd Formula": pace off the length and breadth of any crowd, add the two figures, multiply by seven for a slack crowd, by ten for a dense one.
Then, if you disagree with the cause the crowd is rallying 'round, you divide by 10; if you support it, multiply by a like amount.

22 comments:

og said...

It's Million Man Math(tm)

Stranger said...

It is indeed "million mom math." But a friend who works for the gummitup says the crowd was visible in satellite images. Big crowd. Not a "million" but larger and denser than the "million mom march" a few years ago.

She says 600,000 minimum, 650,000 tops, plus those hidden under trees.

Me? I just listen. And laugh at those who try to say Rev Al's crowd was as large.

Stranger

Nathan said...

I've always wondered why anyone even tries to count these crowds. Knowing the fill percentage ought to be sufficient. Just looking at the crowd and saying, "damn, that's a big crowd" ought to be sufficient. Dayenu, already.

It's clear from the comparative photos that the MLK and Beck crowds were comparable in size. Enough already.

Most folks don't really intellectualize counting, anyway. They still go "1, 2, 3, many". In my opinion, the Beck crowd consisted of more people than you could shake a stick at, plus the stick.

Can't we all just count along? :)

Ed Rasimus said...

The number isn't important. It's the message.

Hypnagogue said...

I am astonished by this formula. I never knew you could calculate area by adding.

Steve Skubinna said...

It did seem odd to me, Hypnagogue, that you add the two measurements. But then they provide a multiplier to apply to that number, so it really has nothing to do with area (which still seems odd). I'd like to see a comparison of this method with those that do measure an area and then apply a figure based on estimated SF per person.

And then compare both with a crowd image that we do have a precise count for, say a sporting event.

Hypnagogue said...

Odd? I'll try to be more opaque. It's absolutely idiotic.

google said...

Multiply, don't add. The article was wrong. I mean, you don't expect Time magazine to be able to do math do you?

Hank

Matt said...

Given that the modern political process basically consists of two armies showing up for a civil war, counting each other, and then the bigger one declaring itself the winner without bothering to actually do any fighting, I'd say it matters.

If a few thousand people show up for a march, most DC denizens will barely notice. If a few tens of thousands of people show up, it'll make the Post, but only because the Post happens to be the paper that covers local events.

If 600,000 people show up for your march, you're essentially doubling the population of DC for the day. And any movement that can do that on-demand is essentially an embryonic revolution.

The MSM wants us disorganized, depressed, and despairing. The numbers don't back them up.

Bubblehead Les. said...

More Math: If 500,000 people took the time, money and effort to spend a hot weekend in D.C. to listen to a bunch of people Speechifyin', I figure that 10x more agree with what was happening there,but they didn't show (for many reasons). That's 5 million Pissed-Off people ready to storm the Voting Places come Nov. But the main question that must be asked is this:

Does the New Black Panther Party have enough Manpower to stop them?

Of, course, this whole argument would be moot if it wasn't for Bush.

Jay G said...

Heh @ Nathan for the Pratchett ref...

Detritus/Angua 2012...

Thomas F said...

More Math: If 500,000 people took the time, money and effort to spend a hot weekend in D.C. to listen to a bunch of people Speechifyin', I figure that 10x more agree with what was happening there,but they didn't show (for many reasons). That's 5 million Pissed-Off people ready to storm the Voting Places come Nov.

How many people outside driving distance didn't come to the Beck event due to the economy, you could double that number with ease.

The House in November, is going to be a bloodbath.

Robert said...

But a friend who works for the gummitup says the crowd was visible in satellite images.

That doesn't really mean anything. A crowd of one is visible from today's satellites. They can damn near read your license plate if the angle is right.

Just sayin'.

Anonymous said...

This is a science that the park service has down to a very small variable. They can count the visitors. They QUIT being able to release numbers during the un-publicised anti-abortion marches and rallies at the Capitol.
The Park Service could tell us within a thousand of how many folks were there. But they dont.

Tim said...

this formula does not make sense (no doubt CNN's reporting). Take a 10 x 10 space. If you "pace it off" you get 3-4 paces in either direction. Let's say 3. 3+3=6 x 10 = 60 people, tightly packed. 60 people! (It would be much larger if you multiplied the numbers) Using his 4 sq feet per person rule, however, you get100 sq feet/4 sq feet per person =25 people.

sumthin ain't right.

Tim said...

Sorry...Time's reporting, not CNN's.

Flight-ER-Doc said...

Yeah, the unit of dimension used is critical. Feet, meters, what?

Michael said...

Furlongs

DirtCrashr said...

One of my compatriots calculated it based on people vs. automobile space when we crossed the Golden Gate Bridge on the 50th amid a really thick mass of bipeds, and later heard reports of the whole bridge sagging. It was one person per washhcloth thick. Thicker than a Dead Concert. I quit public acts of togetherness after that. I can't stand that many people with me.

Steve C said...

I learned math about 12BC (Before Calculators) so this formula set off my BS detector. Also Time wrote it so I'm sure it went thru their rigorous fact checking. I did a little research and came up with the true method. Instead of the pacing nonsense, what you want is the square footage. Then you device the square footage by the amount of space a person occupies. For a tight crowd (subway at rush hour); 2.5 SF, For a good crowd that you can still walk thru; 5SF, for an open crowd around the display tables; 10 SF. Simple.

Scott said...

Folks:
10 square feet is NOT a 10 foot square.
A 10 foot square contains 100 square feet: 10 times 10 square feet.
10 square feet is a box slightly more than a yard (3+ feet) on a side.
About as close as you want to get to a complete stranger.
The aerial crowd photos , using the actual dimensions of the reflecting pool as a basis, show an occupied area of about 1,000,000 square feet. Lincoln Memorial to just past the WWII Memorial and both sides of the pool. Lots of green (unoccupied grass) visible within.
If everyone is a yard apart, that's 100,000. Remember, factor in lawn chairs, blankets, and such.
If it was 500,000+, well...
The crowd would have been WAY more interesting to watch than the speakers!

markm said...

Obviously no one on either the AOL news staff now nor Time Magazine's staff in 1967 passed 5th grade arithmetic. You multiply, not add, for area, and measurement without units is meaningless. They also mixed up "divide" and "multiply" at the last step.

The real formulas:

Area (square feet) = length x width (feet)

Crowd numbers = Area (in square feet) divided by 10 for a loose crowd, to 2.5 for a mosh-pit crowd.

http://en.wikipedia.org/wiki/Herbert_Jacobs#Jacobs_method_for_crowd_size_estimation