WASHINGTON — Crowd counting is far from an exact science, as the varied estimates of President Barack Obama's inaugural crowd Tuesday richly demonstrate.
The Washington Post put the crowd at 1.8 million in Wednesday's editions. Stephen Doig, a journalism professor at Arizona State University in Tempe who specializes in crowd counts, estimated 800,000.
IHS Jane's, a defense analysis firm that used the same satellite image Doig did, came up with 1.271 million to 1.651 million.
CNN, citing IHS Jane's, split the difference in the range and estimated about 1.5 million.
The Associated Press estimated "more than 1 million" and McClatchy "about 2 million." The New York Times cited unnamed law-enforcement representatives who were said to have estimated "more than a million and perhaps as many as 2 million."
Allison Puccioni, the IHS Jane's analyst, took a more disciplined approach. She said she'd generated her estimate from an image that the GeoEye-1 satellite took as it passed over the National Mall at 11:19 a.m. Tuesday. She said that she might have counted clusters of people in areas that Doig didn't include.
Doig said he'd used the same GeoEye-1 image that Puccioni did, plus TV footage and photos from Flickr. He thought that their differences might have stemmed from different density estimates.
"If someone estimates a 'loose crowd' with 10 square feet per person and someone else calls it a 'tight crowd' at 5 square feet per person, the crowd size will be doubled by the 'tight crowd' estimate," Doig said.
Initial estimates that the National Mall could hold around 2 million people were based on an even distribution of visitors on the 2.1 miles of the Mall. In reality, people huddled near the jumbo TV screens so that they could watch the historic moment, creating dense clusters and open spaces in between.
The National Park Service adopted the Washington Post's 1.8 million estimate late Wednesday after District of Columbia mayor Adrian Fenty used it in numerous interviews. So 1.8 million is the official inaugural crowd estimate, albeit a disputed one.
MORE FROM MCCLATCHY