Tuesday, June 16, 2009

Baker's Dozen: How many cities?

While I was putting together the previous post, on crowdsourcing, I tried to look up how many cities there were in the US (for some reasonable definition of "city"). This seemed right up Wolfram Alpha's alley, so I tried "How many cities are there in the US?" Alpha did something I hadn't seen it do before. It answered the question, but not well.

But at least it's pretty clear where it went astray. For whatever reason, it assumed I was interested in the largest cities in the US and gave me the top five. There was a "more" link, but that just expanded the list to the top 10. Who knew only nine have over a million people? (San Jose is tenth with about 900,000)

Unlike True Knowledge, Alpha chooses not to clutter its display with a list of web hits. That's probably why I missed the "web search" button the first time around. Chasing that takes me to Google. The top hit is WikiAnswers. The answer states that "Because many towns are considered counties in some States it gets complex" and points me at City-Data.com, which is supposed to have all of them. Maybe it does, but it doesn't seem to answer the question directly.

OK, where did Alpha get its information then? Apparently from a variety of sources, including the CIA fact book and the US Census Bureau. So maybe look there. There's also a link to the Wikipedia article, and visually skimming that I see that "In 2006, 254 incorporated places had populations over 100,000."

That's a decent answer. 100,000 is a commonly used if somewhat arbitrary cutoff point for citihood. It wasn't really what I was after, though. I was looking for places one might use in a query of the distance from place A to place B, and I would expect that plenty of places with under 100,000 people would qualify. But that'll have to wait.

So ... Alpha to Google to WikiAnswers to a dead end, Alpha to Wikipedia to a plausible answer; two pointers toward the US Census, which is where I would have gone looking if I hadn't had search engines to guide me.

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