geocoding our nation's schools - blue raster nces stats-dc 2012 presentation

GEOCODING OUR NATION’S SCHOOLS

Presented by Tai Phan & Adrienne AllegrettiNCES, Blue Raster

NCES STATS-DC 2012 – July 13, 2012

PRESENTATION OUTLINE

Introduction

Overview of Geocoding

Data Preparation

Selecting a Geocode Solution

Live Demonstration

Overview of SDDS Updates

Summary/Q & A

WHAT IS GEOCODING?

The process of finding associated geographic coordinates (latitude and longitude) from other geographic data, such as street addresses, or zip codes (postal codes).

HOW DOES GEOCODING WORK?

Address Interpolation:

HOW DOES GEOCODING WORK?

Other Techniques:

ADVANCEMENTS IN GEOCODING

THEN

ADVANCEMENTS IN GEOCODING

NOW

To support spatial analysis and provide geographic context to a schools location Geocoded schools can be overlaid with

other geographic layers such as: School Districts Locale Codes Counties Congressional Districts And more…

WHY DOES NCES GEOCODE SCHOOL ADDRESSES?

LOCATION MATTERS

HOW TO PREPARE DATA

Invest in your address data quality and check for errors before you begin: Spelling Numeric address ranges Missing information

Garbage In

Garbage Out

IMPLICATIONS OF GEOCODING ERRORS

Accuracy of geocoding dictates quality of research

Schools geocoded incorrectly can mean lost funding

Unable to respond to an emergency appropriately

HOW TO PREPARE DATA

Format it in a style that the geocoder can handleUse the locational address, not the PO Box or Administrative address of the school

HOW TO PREPARE DATA

Bad: FMLY CHLD CTR 1411 LNCLNWY W, MISHAWAKA, IN, 46544

HOW TO PREPARE DATA

Good: 1411 LINCOLN WAY WEST, MISHAWAKA, IN, 46544

SELECTING A GEOCODE SOLUTION

Things to consider: Budget Number of Records Infrastructure Number of Individuals Needing Access Frequency of Geocoding Sensitivity of Data

1ST APPROACH: LOCAL/INTERNAL

In House

Millions of

addresses

Economy of Scale

Datacenter and/or

Cloud Services

Sensitive Data

GEOCODING ON THE DESKTOP

Prerequisites ArcGIS Desktop Basic Prepared Address Table Reference Data (NAVTEQ, TOM TOM,

TIGER) Address Locator (Composite)

ON THE DESKTOP – COMPOSITE LOCATOR Multiple locators used in a cascading

fashionAddress

Match• Best

Match

Street Centroid Match

• Decent Match

Zip Code Match

• Acceptable Match

ON THE DESKTOP – USER INTERFACE

ON THE DESKTOP - OPTIONS

ON THE DESKTOP - OUTPUT

ON THE DESKTOP SUMMARY

Great way to go if software and reference data is already in-house

Can geocode more than 350,000 addresses per hour

Data maintenance and support No custom development required

2ND APPROACH: GEOCODING WEBSITES

Geocoding

Websites

Hundreds of

address at a time

Excel and Web Browser

Points on a Map

Publicly available

data

GEOCODING WEBSITES:

Single Address Look Ups: ArcGIS Online - http://

www.arcgis.com/home/webmap/viewer.html http://geocoder.us/ http://itouchmap.com/latlong.html https://webgis.usc.edu/Services/Geocode/Default.aspx

Batched or Multiple Address Look Ups: ArcGIS Online - http://

www.arcgis.com/home/webmap/viewer.html http://batchgeo.com/ http://www.gpsvisualizer.com/geocoder/

ARCGIS ONLINE – SINGLE ADDRESS

ARCGIS ONLINE – MULTIPLE ADDRESSES

ARCGIS ONLINE – MULTIPLE ADDRESSES

ARCGIS ONLINE – MULTIPLE ADDRESSES

3RD APPROACH: WEB APIS

Web

APIs

Hundreds to

Thousands of

addresses at a time

Publicly Accessibl

e DataCustom Development

Required

GEOCODING APIS AVAILABLE FOR CUSTOM DEVELOPMENT

ArcGIS Online Yahoo Bing Google MapQuest Geonames

Be sure to read the terms of service and know the limitations. For example, when using Google, you must display your results on a Google map. Google limits requests to 2,500 addresses, etc.

GEOCODE RESULTS

The Hit Rate is the number of addresses that are geocodable

The Match Scores tell you what level of accuracy a particular address was geocoded.

- Country- Region (state, province, prefecture, etc.)- Sub-region (county, municipality, etc.)- Town (city, village)- Post code (zip code)- Street- Intersection- Address

- Premise or Roof Top

HIT RATES AND MATCH SCORES

No Matches Found

HIT RATES AND MATCH SCORES

Zip Code Centroid

HIT RATES AND MATCH SCORES

Street Name Found

HIT RATES AND MATCH SCORES

Street Address Found

HIT RATES AND MATCH SCORES

Address Point Found (Highest Accuracy!)

OTHER OPTIONS - PLACEFINDERS

OTHER OPTIONS – REVERSE GEOCODING

DEMO – SDDS GEOCODING PROTOTYPE

WHAT ARE LOCALE CODES?

WHAT ARE LOCALE CODES?

Read more: http://nces.ed.gov/ccd/rural_locales.asp

SCHOOL BOUNDARY PROJECT

Project Background 350 largest districts already collected 1000+ collected by the end of the year

That’s over 50% of students

SCHOOL BOUNDARY PROJECT

Where to find the data

Can be downloaded from SDDS Standard Map Viewer.

WHAT’S NEW IN SDDS MAPVIEWER

Map Viewer Standard Census 2010 ACS 5yr Estimate

2006-2010 Public School

Boundaries Middle Elementary High

Promise Neighborhood Schools

Map Viewer Mobile Migration to

GEOCLOUDhttp://nces.ed.gov/surveys/sdds/index.aspx

Q & A

FOR MORE INFORMATION:

Adrienne Allegrettiaallegretti@blueraster.com

703-842-0171

www.blueraster.comblog.blueraster.com

Tai PhanTai.Phan@ed.gov

202-502-7431