

Explore local data: Crime, schools, and home prices across the nation - shashashasha
http://www.trulia.com/local/

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ck2
Sigh, every site like this reminds me how much I miss Google Real Estate
Search - why did they kill that.

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sukuriant
Good work. This is truly much better than any of the similar services I've
seen in the past. I especially like that it's an easy lookup for what looks to
be the complete array of crimes in all areas; and, the heatmap is helpful.
What is it normalized based on?

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shashashasha
Hi, thanks so much! The heatmaps are normalized on a per county basis, and red
is a 97-98 percentile block in terms of crime density.

We're not doing per capita normalization because we haven't had that data on a
per block basis, but definitely looking in to ways to start to do more
granular normalization.

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abs314159
Could you normalize at the census tract level? Better yet, assign average
occupants, shoppers, cars parked, etc. to the locations at which the crime
occurred.

A bigger issue is variance in less dense areas. It looks like what you're
doing today is simple counts whereas for areas with lower crime rates, more
history might provide a more stable crime rate. It might also be useful to
weight against a demographic prediction of crime or at least average the crime
rate over the period that the demographic prediction is stable.

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sukuriant
> A bigger issue is variance in less dense areas. It looks like what you're
> doing today is simple counts whereas for areas with lower crime rates, more
> history might provide a more stable crime rate. It might also be useful to
> weight against a demographic prediction of crime or at least average the
> crime rate over the period that the demographic prediction is stable.

The purpose of this tool seems to be to decide where to live. Since the
demographics of cities change over the years, what is the advantage of looking
at more-past demographics?

Second, demographic instability is a very real attribute of neighborhoods, and
it may be correlated with higher crime. I imagine you're trying to reduce that
visibility. Why? Again, the goal is to give a current view of the crime in the
area, not what the crime will look like when things calm down.

In all, I think it's good how it is, as it represents exactly what I would be
looking for when I examine crime/local facilities/housing prices.

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Retric
This is useless for my area 22202 Arlington VA. You basically mark all areas
with highrises as red, and areas with single track housing as green. Sorry, if
there is a row of 22 story building on one block and 3 blocks away is single
family dwellings of course there is going to be more crimes where there is 30x
the number of people.

<http://www.trulia.com/local/#crimes/washington-dc>

PS: <http://en.wikipedia.org/wiki/File:ArlingtonTODimage3.jpg> _High density,
mixed use development is often concentrated within 1/4 to 1/2 mile from the
County's Metrorail rapid transit stations, such as in Rosslyn, Courthouse, and
Clarendon (shown in red from upper left to lower right)._
<http://en.wikipedia.org/wiki/Arlington_County,_Virginia>

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sukuriant
Fair enough. Then make the influence of each crime inversely proportional to
the number of people there. All of that said, don't go to the smooth spots of
the function that aren't current and declare "this is the crime rate of this
place". That was my point

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sixQuarks
Ummm, according to the San Francisco heat map, Hunter's Point looks like a
very safe area while China town seems way more dangerous. I don't know how
accurate this is.

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Yen
Here's a preview of the violent crime map - it's colored based on the
percentage of violent crimes in a given area, for areas with > 50th percentile
crime for the county.

As you can see, Hunter's Point definitely sticks out in this map.
<http://dl.dropbox.com/u/338114/Screenshots/02l.png>

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sixQuarks
OK, that looks way more useful. thanks

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geogra4
It would be nice to have an absolute scale so one could compare adjacent areas
in different counties.

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functionform
I'm not clear on the available data, is there a date range somewhere? Very
nice btw.

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mmuro
Data is wildly incomplete in some areas, but it's pretty cool nonetheless.

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superchink
Anyone know if there are any plans to make this data available via an API?

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danso
Where is this service drawing its crime data for? Specifically, for NYC:
<http://www.trulia.com/local/#crimes/new-york-ny>

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shashashasha
We're partnering with SpotCrime.com and CrimeReports.com for their crime data,
who both work with police agencies to syndicate their data. In most cases our
crimes are updated on a daily or weekly basis.

Unfortunately, New York doesn't publish their crime data in a granular way. I
think much of SpotCrime's data is scraped from various sources including
newspapers, and we're showing what we get from them. This is a bummer for us,
as it's probably not complete, but hopefully New York will publish their data
soon!

