Was Harlem really a hotbed of illegal fireworks complaints?

It looked that way on a map by DNAinfo. But a closer read reveals that the zip code with the most fireworks complaints to 311 had ... four. Over four days.

In April, the same site, the Daily News and lots of other websites tittered over fireworks of a different sort — 311 complaints of loud sex. Brooklyn's 11221 Zip Code got a triple-X rating as one of the loudest for lovemaking. But click on the map, and you see eight complaints there for an entire year.

"Sometimes people are looking for the fun story more than the scientifically rigorous analysis," says Ben Wellington, who writes the data blog I Quant NY, and did a great writeup about 311 noise complaints for the New Yorker, using the city's open data portal. "That is one of the great things about public data, because when people write about things like 311, people like you can go in and ask questions."

First question: What's the denominator? Because, in this case, size matters.  There are 32,000 apartments and other housing units in zip code 11221. That's one complaint for every 4,000 apartments over an entire year. A few alternate interpretations of the data could be that New Yorkers are really quiet, that they are very tolerant of their neighbors ... or that almost nobody calls 311 about sex.

Which brings us to another question: Who's in the sample? For this data, it's people who have chosen to complain. And Wellington reminds us that some people feel more comfortable, or entitled, to call an official phone number about noise.

And according to his work, the highest number of people who complain about noise to 311 per capita are in the southern half of Manhattan and in northern Brooklyn.