Archive for

The Importance of Outliers

by John Hayes, GIS Applications Specialist and Jay Colbert, GIS Project Manager

When delivering data to large groups of people it is critical that the information be as accurate as possible.  At SAVI, we follow as many as five quality control (QC) steps to ensure that users can be confident with the numbers that they use in their grant applications, community assessments, and strategic planning efforts.

Part of the process includes outlier analysis, which helps us to identify values by year that differ the most outlier from other values for that indicator. Outliers are important for two reasons: 1) they may represent an error in the data that needs to be fixed; 2) they may represent the first indication of an important new trend.

Let’s look at some of the interesting things that have popped up during our data analysis.

This chart shows a data value that our outlier analysis found as unusual. 2011 showed a strong increase in average number of hospitalization days due to injury and poisoning in Marion County. Further investigation into the raw data revealed a case of an unfortunate patient who had spent more than 40,000 days in the hospital for a broken arm. Obviously this was a data error and we were able to fix it.


After reprocessing the data the chart looked like this…


Other finds are not so easily fixed. In the chart below we found a strong decrease in the number of mental health hospitalizations in Hendricks County in 2011. The data showed a large drop for mental health hospitalizations in one particular hospital in Hendricks County, but we are still working with the data provider to determine if it is a real trend or a data error. In the interim we have removed the suspect values from SAVI.


Another possible result in outlier analysis is the identification of new trends. Some examples follow.

One consequence of the recent recession is lower employment. The data highlights this trends in the case of Morgan County, where we can see that there were fewer males employed in 2010 than in 2000.


As Marion County continues to move towards a higher minority population, data reveals that the white population has declined in recent years. The decrease is even stronger among children as noted in the following chart.


Home loans in general decreased sharply in recent years with the housing downturn, and home improvement loans were no exception. The chart below illustrates to what extent these loans fell in the Indianapolis-Carmel MSA. But, also notice that there was a small increase in 2011, the first since 2006.


Juvenile runaways showed as a strong upward outlier in 2010, but by 2012, the numbers fell to the lowest level since 1999.


In recent years, the trend for juvenile arrests in Marion County has dramatically decreased.


While total juvenile arrests have been decreasing in recent years, juvenile arrests for gang-related activity increased sharply in 2011 and 2012. There are many possible reasons for this. One, as reported by WRTV, is that gang activity is expanding and spreading in Indianapolis and surrounding suburbs.


Which of these examples do YOU find most interesting?


Your resource for nonprofit excellence

by Debbie Pidgeon

Whether here at the blog each week, on our social media pages every day or at our conference event each fall, the Governor’s Conference on Service and Nonprofit Capacity Building wants to help your organizations maximize impact and strengthen communities.

We’ll share with you opportunities for networking and collaboration. We’ll provide you access to tools and experts that will help you improve effectiveness and efficiency.


2012 Conference keynote session

As part of this commitment, we’re growing our annual Conference event to two days this year, October 3-4, 2013.

We’re also welcoming a new host agency, the Office of the Indiana Attorney General, which joins the Indiana Office of Faith-Based and Community Initiatives and SAVI Community Information System as event organizers.

Now that we’ve opened event registration this week, I want to share with you more details on who can benefit from attending and what attendees can expect.

We strongly encourage attendance from nonprofit professionals who work at: social service agencies; faith-based organizations; neighborhood and community-based organizations; libraries; government agencies; consultants that work with nonprofits.


2012 Conference breakout session

On day one of the Conference (we’ll share more on day two in an upcoming post), we’ll help attendees build skills in these areas:

  • strategic planning
  • funding/finance
  • marketing/social media
  • governance
  • volunteerism
  • collaboration

You can view session descriptions at the Conference website, and we plan to include more networking opportunities this year, including an open luncheon format on day one.

The first day of Conference will wrap up with the Indiana Governor’s Service Awards (which accepts nominations until July 19). The awards, the highest honor for volunteer work in our state, will be distributed in eight categories at a ceremony inside the State House.

Take a closer look at the agenda of what we have planned and let us know what you’re looking forward to and why?

2131fc4 Blog author Debbie Pidgeon is the Chief Operating Officer at the Indiana Office of Faith-Based and Community Initiatives, where she overseas the office’s role as a Conference co-host.

Why (and how) you should take advantage of SAVI’s property data

By John Buechler, Director of Geoinformatics, The Polis Center

In Indiana, the county assessor identifies and appraises all taxable property. To accurately value a property, the office collects information such as square footage, construction type, and year built. The assessor then provides this information to the Indiana Department of Local Government Finance (IDLGF)—the department responsible for ensuring that property tax assessment and local government budgeting are carried out in accordance with Indiana law. To ensure compliance, IDLGF annually reviews and approves the tax rates and levies of every one of Indiana’s political subdivisions that has tax levy authority, for example, counties, cities, towns, townships, school corporations, etc.

SAVIAnyone can go to IDLGF’s website and retrieve an individual property’s assessed value and property taxes by entering an address, owner name, or property identification number.

Additionally, SAVI collects the IDLGF property assessment and tax data from the Indiana Business Research Center and links it with the parcel boundaries from Indiana Map in order to generate statistical summaries by census tracts, neighborhoods, and jurisdictions for 9 counties in Central  Indiana.

But why is this data important? Your first reaction may be that you don’t have much need for such comprehensive data. But I’ll argue that you do. In fact, these data can provide value to everyone from an individual taxpayer to a nonprofit organization to a library or school district…the list goes on and on.

Here are a just a few questions that communities and organizations can answer using the property data in SAVI.

1. WHERE DO RESIDENTIAL PROPERTY TAX DISPARITIES EXIST? The property data reveals how much residents pay in taxes, which can help identify if there are tax disparities in neighborhoods, or even according to housing unit type.

2. WHAT IS THE MIX OF LAND USE?  Land use can help you understand the basic composition of an area (i.e., how much is residential as compared to commercial or industrial), which is valuable because it highlights open spaces and opportunities for new development. Land use data can also put other data in perspective. For example, data tells us that robbery rates are often higher in commercial areas. So, when looking at crime statistics for a particular neighborhood, knowing that 60% of properties in that neighborhood are commercial will help you to interpret the significance of the higher robbery crime rates.

3. WHICH AREAS HAVE OLDER HOUSING STOCK AND REQUIRE SPECIAL REDEVELOPMENT CONSIDERATIONS?  Older homes (particularly those built before 1980) often contain lead-based paint on the interior walls, the outside of the home, the window frames, and more. And according to the US Environmental Protection Agency, exposure to lead is the “number one environmental threat to the health of children in the United States.” So it is important for neighborhoods and health departments to understand where lead exposure may exist.

The following map illustrates how you can use SAVI to visualize the areas with older homes that may have lead-based paint.  It displays the percent of residential dwellings in each census tract that were built before 1980 in Marion County and parts of the surrounding counties.


These were just three examples of how the property data, particularly when coupled with SAVI’s statistical summaries and visualization tools, can be beneficial to communities and neighborhoods.

If you’ve used this data in other ways, tell us your story. We’d love to know!

Data shows that citizenship does not guarantee immigrants will become active voters

Photo courtesy of Toledo Blade

Photo courtesy of Toledo Blade

By Elizabeth L. White, Marion County Clerk

This Wednesday, just before we celebrate our country’s Independence Day, about 100 immigrants will take an oath of allegiance to the United States of America at a special ceremony held by the U.S. District Court of Southern Indiana at the home of President Benjamin Harrison in Indianapolis.

This joyous occasion celebrates the very best of our country and is a reminder of how fortunate we are to live in a community that welcomes people seeking a better life.

I’m humbled for the chance to be able to participate, welcoming our newest Hoosiers and encouraging them to register and vote.

Since 2009, our office has registered more than 6,000 naturalized citizens living throughout southern Indiana. Some are very sober and reflective about registering to vote for the first time; others are elated that they now are full members of a country where the fundamental fairness of elections is a cornerstone to our democracy.

The University of Southern California estimates naturalized citizens comprised about 2.1% of Indiana’s voting population in 2012, compared to 3.6% nationally. Historically, their participation in elections lags those who are U.S.-born, though recent evidence indicates a slight upward trend.

Interestingly, the data suggests this discrepancy has more to do with barriers in registering to vote rather than the act of voting itself; once registered naturalized citizens participate in elections at a similar rate to those that are U.S.-born. So how do we overcome this hurdle many new Americans face?

One suggestion is to look at the registration form itself. Many states offer voter registration forms in English or Spanish, creating a language barrier for those non-English speakers to fully integrate into our community.

We can also work on our outreach efforts. My office has made it a priority to attend nearly all of the naturalization ceremonies over the last four years. This simple act demonstrates our commitment to inclusiveness.

Hopefully, these new voters will now go back to their home counties and actively participate in the election process whether it’s casting a ballot on Election Day, running for elected office or volunteering to serve as a poll worker.

Our right to vote is the essence of democracy: that everyone can participate, that everyone has an equal voice. As our newest citizens celebrate their first Independence Day as Americans, we should all be reminded of what that citizenship requires – participation.

Introducing Indiana’s Immigrants

By Jay Colbert, GIS Project Manager, The Polis Center

Recently, it’s been impossible to open a newspaper or turn on the news without hearing about immigration reform. Politicians and citizens alike must consider how to address the fact that the waves of immigration (legal and illegal) are increasing.

Consider Central Indiana. In the past 40 years, the foreign-born population has increased by 622%—a much more significant growth than the 37% percent increase in US-born residents.

As the following chart shows, Marion County has the highest foreign-born population in Central Indiana. Of the county’s 2010 foreign born, only about 30% are naturalized citizens.


America has a long history of attracting immigrants. Between 1820 (when immigration records were first documented) and 1920, almost two-thirds of all immigrants chose to migrate to the US (Indiana Historical Society, Immigration and Ethnic Heritage). In fact, unless you are Native American, your family, at some point, immigrated to America within the last 400 years.

Today, the US is still the most popular destination for migrants with a 2011 immigrant population of more than 40 million (Migration Policy Institute, Migration Information Source).

Note that in the following map, Pike and Wayne townships have the highest percentages of foreign born in Marion County at greater than 9.5%.


Most immigrants in Indiana migrate from Mexico. In Marion County, for example, 46% of the foreign-born population was from Mexico. The following chart shows the breakdown of the county’s foreign-born population according to country of origin.


Many people move to the US based on its historic portrayal as the land of opportunity. Immigrants come in search of more money, better jobs, and improved quality of life. The following chart compares which occupations and industries are popular among natives and foreign born. For both native and foreign-born citizens, the most common occupation is in management, business, sciences, and arts, and the most common industry is education, health care, and social assistance.


In Marion County, the trends are different. The most common occupations for foreign-born workers are as follows:

  1. Service
  2. Production, transportation, and material moving
  3. Management, business, and science, and arts
  4. Sales & office
  5. Natural resources, construction, and maintenance

And the most common industries for foreign-born workers in Marion County are:

  1. Arts, entertainment, and recreation, and accommodation and food services
  2. Educational services, and health care and social assistance
  3. Manufacturing
  4. Retail trade

Finally, I want to share with you some of the facts about the foreign-born population in Marion County that I found particularly interesting or surprising.

  • There is no statistically significant difference in median age between the foreign-born population and those born in the US. This is mainly because there are relatively few foreign-born children and seniors. In fact, more than 50% of the foreign-born population is between the ages of 25 and 44.
  • 90.5% are minorities
  • Foreign-born people are more likely to live in married-couple households than natives and are more likely to be married than natives
  • Foreign-born people are just as likely as US-born to hold a graduate degree.
  • Foreign-born people are more likely than native-born people to be in the labor force and to be employed.

For community leaders and nonprofit and service organizations, understanding the demographics and data associated with those immigrating to our communities is invaluable. In developing a better understanding of the people who comprise our communities, we’re better equipped to provide the resources and assistance that they need.

Stay tuned for Wednesday’s post when guest blogger Elizabeth White, Marion County Clerk, discusses the process of naturalization.


Enter your email address to follow this blog and receive notifications of new posts by email.

Follow me on Twitter