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<p class="MsoNormal"><span style="color:#1F497D">Hi Duane,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">There have been a lot of good suggestions already. Hopefully here’s another!<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">If by “correlation” you mean something like an observable, mappable pattern that shows up when you put all of the data attributes on a map, you might consider looking at the “Conditional Maps” you can create
using <a href="https://geodacenter.github.io/">GeoDa</a>, a free, open source software application by the University of Chicago's
<a href="https://spatial.uchicago.edu/">Center for Spatial Data Science</a>, which focuses on exploratory spatial data analysis.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Here’s an example of what conditional maps look like using some of the sample data that GeoDa provides:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><img border="0" width="791" height="573" id="Picture_x0020_1" src="cid:image002.jpg@01D48670.1C908740"><span style="color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">This is from the National Consortium on Violence Research and shows homicide rates per 100,000 in Atlanta, Georgia
<i>conditioned </i>on two variables: resource deprivation (or poverty) and police expenditures. Both poverty and the amount spent on police are split into three quantiles (think Low, Medium and High), but they can easily be split up using any other system,
from equal intervals to natural breaks to standard deviations.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Here’s how you read the output:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">The bottom left map only displays counties that have
<i>both</i> low poverty rates <i>and</i> low police expenditures. The homicide rates for those counties are then visualized like any other choropleth map. (Here at FREAC we would recommend using the US National Grid to display this data, but I’ll leave that
for another time. </span><span style="font-family:Wingdings;color:#1F497D">J</span><span style="color:#1F497D">) By contrast, the top right map only shows homicide rates for those counties that have both high poverty rates and high police expenditures, the
top left map shows low poverty and high police expenditure, <i>etc.</i><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">What pops out? At first glance, we can tell from the upper right map that the south side of Atlanta has a mix of high poverty, high police expenditures
<i>and </i>higher homicide rates, especially Taylor County (which, incidentally, was still holding segregated proms in the 2000s). Perhaps also interesting is Fulton County in the middle right map: the heart of the City of Atlanta has high poverty, only medium
police expenditure, and a very high homicide rate. You’d have to do a lot more investigating to show that the two variables in question were
<i>causing</i> the high homicide rate (and not just <i>correlated </i>with it), but at least exploring the data in this way points you in a certain direction.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I hope this makes sense. You could imagine mapping crime rates within census tracts while using the number of street lights and dilapidated housing in those census tracts as the conditional variables. There’s
a tutorial that walks you through how to create conditional maps (and a whole lot more) in GeoDa
<a href="https://geodacenter.github.io/workbook/3a_mapping/lab3a.html#conditional-map">
here</a>. I recommend the whole series!<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">All the best,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Philip Griffith<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b>From:</b> SHRUG-L [mailto:shrug-l-bounces@lists.dep.state.fl.us]
<b>On Behalf Of </b>Duane Treadon<br>
<b>Sent:</b> Tuesday, November 27, 2018 9:49 AM<br>
<b>To:</b> 'SHRUG-L@lists.dep.state.fl.us' <SHRUG-L@lists.dep.state.fl.us><br>
<b>Subject:</b> shrug-l: Been a while since I've done this...<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black">Hi all,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black">I need a little help shaking the cob webs out of my brain on how to set up an analysis process to look at correlation. My Chief has asked me to look at crime and see if there
is any relationship between it and dilapidated housing and also look at street lighting. I am lucky in that I have access to all the data needed and it is easy to extract, geocode, and add to our geodatabase for use in ArcMap or ArcPro . We have crime data
for the past several years, our Building Dept. keeps a good record on housing conditions throughout the city, and the Electric Dept. has all street lights mapped out in our GIS already. I have ArcAdvance and access to all the spatial analysis extensions and
tools available as well as ArcPro and its tools/workflows.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black">What I need help on is deciding what tools to use and how to interpret the results. My thought is to look at each element as it relates to crime. Look at crime and dilapidated
housing and how it falls on the map. Then crime and street lights in the same way. Then bring it all together to see if there is a stronger pattern with all three elements.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black">So what tools should I use? Any publications or exercises out there that explain the processing of data to determine if there is a correlation. Any pdfs you can share that
explain the tools in ArcMap that I should use. Are ESRI products not the way to go? Is there an easier solution for looking at the data? <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black">p.s. as a follow up my Fire Chief would like me to look and see if there is an increase in fire calls that follows the crime.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black"> <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black">Thanks for any info you can provide.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><u><span style="font-size:16.0pt;font-family:"Times New Roman",serif;color:black">Duane 'JT' Treadon, GISP<o:p></o:p></span></u></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black">Director of Geographic Information Systems | City of Thomasville | Information Technology<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black">Office: (229) 227-4023 | Cell: (229) 221-5991
<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-family:"Times New Roman",serif;color:black">111 Victoria Place | P.O. Box 1540 | Thomasville, GA | 31799
<o:p></o:p></span></p>
<p class="MsoNormal"><i><span style="font-family:"Times New Roman",serif;color:black">The Power of Community. The Power of Service.
<o:p></o:p></span></i></p>
<p class="MsoNormal"><span style="font-family:"Times New Roman",serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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