Recently there’s been a bit of controversy surrounding Glen Beck’s march on Washington, and I’m not talking about the content of the march.

Rather, I’m talking about the number of people who actually attended the rally. Some people have pegged the number at 100,000. Other news reports have put it around 300,000 or as has as 400,000. So, which is it?

The truth is, no one knows. And, unfortunately, there’s no independent source to ask to get a real answer. If you ask the organizers, you are likely to get a high number. They have a vested interest in bloating the number to make it appear as large as possible. If you ask an opponent of the event who might have been there to take it all in, you’re likely to get a low number.

What about asking police? Couldn’t a police officer be considered a non-biased source of this information? Generally, yes. But, unfortunately with an event the size of Beck’s that takes place in a large, open space, there’s really no way for police to provide a specific number.

I know all about this, because I’ve dealt with it countless times. How do you estimate the number of people at the dedication ceremony for the DDay Memorial when it’s standing room only? How do you estimate the number of people at the candlelight vigil/march in Washington, DC four days after the 9-11 attacks? How do you estimate the number of people at the final, outdoor campaign rally for a statewide candidate? How do you estimate the number of people in the ballroom of the Richmond Convention Center attending the inauguration of a governor?

There are times when I will actually attempt to count the people. But, anything over 500 or so, and that process becomes tedious and unreliable. At times, I’ll rely on a police estimate, but this generally only works when an event is indoors and the event doesn’t exceed 1000 people or so. At times, I’ll rely on ticket sales, but most events don’t require tickets.

You see why this process can be so unreliable. But, to the people involved in the issue (on either side of the debate) the number matters; which is why there’s been so much talk about how many people were at Beck’s event.

How many people were there? My guess is somewhere in the middle between the low and high estimates. But, it’s just a guess.