StreetScore scores a street view based on how safe it looks to a human • Hacker News Board

Re: StreetScore scores a street view based on how safe it looks to a human

#41

Post by icommenttoo » Sat, Jul 26, 2014, 12:57 PM UTC

jrockway wrote: post #33

awhitty wrote: post #14

Earlier quoted context omitted.

This isn't the best visualization, but I just spent a couple minutes overlaying the New York map with Trulia's crime risk heat map[1,2]. I think the important takeaway is that the green dots visible in the red areas can be interpreted as false negatives for danger. Of course, this is a really, really rough sketch so take it with a grain of salt. [1]: http://www.trulia.com/local/new-york-ny/tiles:1|points:1_cri... [2]…

The crime map seems awfully suspicious to me. It appears to be more of a population density map than anything. All the red areas south of 34th St. just look like common places for people to hang out (and drink alcohol). I think what people really want is a crime map that plots crimes committed at random, rather than drinking buddies beating each other up. I also took a look at vermont, and the red areas were because…

Check this map instead http://i.imgur.com/QwvATt1.jpg The authors already did that analysis, but they incorporated population, area, age, income and perception of safety into a statistical model used to predict violent crimes.

It is important to go beyond the bivariate case here. Comparing streetscore to crime is too simple to be meaningful if other co-variates are not taken into account. For the full description (http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna...)

Re: StreetScore scores a street view based on how safe it looks to a human

#42

Post by Houshalter » Sat, Jul 26, 2014, 1:48 PM UTC

ijk wrote: post #27

electromagnetic wrote: post #22

Earlier quoted context omitted.

I would assume foliage is correlated to wealth. The most affluent areas of town in my city are generally placed on half acre lots (the old city has some that are on acre plus lots inside the city), upper middle class are on the 1/8th to 1/4 acres lots. I live in the original limits of the city, my house is 100 years old and sits on 1/16th of an acre. I'm solidly middle class and my neighbourhood feels it. The biggest…

> I would assume foliage is correlated to wealth Likely. Lawns have pretty much always been conspicuous consumption: Versailles is sometimes considered the source of the first modern lawn, as opposed to a pasture.

In general, but the correlation isn't perfect. E.g. compare Toledo, Ohio to Toledo, Spain. http://www.newworldeconomics.com/archives/2010/022110.html

Some places will have much more green area just because they have much more open space, or empty areas. A more compact or older city will have less space, less green area. But not necessarily because poverty.

Re: StreetScore scores a street view based on how safe it looks to a human

#43

Post by Houshalter » Sat, Jul 26, 2014, 2:39 PM UTC

icommenttoo wrote: post #39

suprgeek wrote: post #19

How safe does this street "look" to a Human? NOT How safe is this street? Very important distinction - I would suggest changing the name of the project to "PerceivedStreetScore". What is now needed is actually part 2 of this project - one that pull records from City/County/Federal crime stats, overlays them with a Map and then actually produces a "ActualCrimeScore" for each of these highlighted streets. Then compare…

If you look at the 2013 paper from this same group you will find that this is exactly what they did ( http://pulse.media.mit.edu/papers/ ). Even further, they used geospatial statistics techniques to control for the effects of the income, area, and population in an area, and hence, developed a model that incorporated not only perception, but also demographics, when predicting the location of homicides.

From the site's FAQ:

>StreetScore is a machine learning algorithm that predicts how safe the image of a street looks to a human observer. We trained StreetScore to predict perceived safety using a 'training dataset' consisting of 3,000 street views from New York and Boston and their rankings for perceived safety obtained from Place Pulse — a crowdsourced survey.

Re: StreetScore scores a street view based on how safe it looks to a human

#44

Post by jamesbritt » Sun, Jul 27, 2014, 6:44 PM UTC

hawkharris wrote: post #31

It's actually well understood which landscape features contribute to or prevent crime. Things like sidewalks and bright street lamps have a positive effect (no surprise there). Bushes, certain fences and other objects that obstruct the view from the road can have a negative effect. As a reporter I once did a ride-along with a police sergeant who took it upon himself to cut a set of hedges (with the property owner's p…

Things like sidewalks and bright street lamps have a positive effect (no surprise there).

There may be some surprise there.

The correlation between street lighting and safety is not obvious.

"In 2008, PG&E Corp., the San Francisco-based energy company, reviewed the research and found 'either that there is no link between lighting and crime, or that any link is too subtle or complex to have been evident in the data.'"

http://www.bloombergview.com/articles/2013-02-24/turn-down-t...

http://www.popcenter.org/responses/street_lighting/2