Secondary Data
Census and TIGER
Why Secondary Data?
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Context (geographic, temporal, social)
for primary data.
Secondary data may provide validation
for primary data
Secondary data may act as a substitute
for primary data.
Types of Secondary Data
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How to find it
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Official
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Unofficial
Unofficial Secondary Data
Sources
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Private research results
Research reports, research papers,
textbooks
Opinion polls
Market research
On-line databases
Anecdotal/hearsay
Official Secondary Data
Sources
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Agriculture
Business/Industry
Crime
Education
Finance
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Energy
Environment
Health
Transport
Weather
Agriculture
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USDA
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FAO
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Farm Bureau Federation
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Babcock
Business / Industry
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STAT-USA/Internet (US Dep. of
Commerce, not free)
Consumer Expenditure Surveys
(Bureau of Labor Statistics)
Internal Revenue Service
Crime
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Bureau of Justice Statistics
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FBI
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Crime & Justice Electronic Data
Abstracts
http://www.ojp.usdoj.gov/bjs/dtdata.htm
Education
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National Center for Education Statistics
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School District Data Book (ORST)
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National Science Foundation
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UNESCO
Environment
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EPA Envirofacts
EPA EnviroMapper
Facility Information
Hazardous Waste Data
Superfund
Toxics Releases Inventory
Water Discharge Permits
ScoreCard
Right To Know
Health
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National Center for Health Statistics
(CDC)
Social Security Administration
Geophysical
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NOAA
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USGS
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US Forest Service
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Soil Conservation Service
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Dep. of Natural Resources (DNR)
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Dep. of Conservation
Transportation
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Department of Transportation
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Bureau of Transportation Statistics
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State Highway Departments (CA, TX)
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Regional Transport Authorities
Census
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Structure
Timing
Population
Organization
Analysis
Presentation
Geographical Hierarchy
Variables
Census Geographical
Hierarchy
Region
Division
State
County
County subdivision
Place (or part)
Census tract (or part)
Block group (or part)
9 mio. Census blocks
Census Household
Variables
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Number of persons 
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Age and gender
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Race
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Language
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Income and poverty
Education
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Employment
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Citizenship
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Vehicles for commute
Disability
Homeownership status
Vacancy
Rent and value of
housing
Age and type of structure
Plumbing and Kitchen
Heating
Examples of Census
Variables
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Accommodations
Agriculture
Alaska Natives
Arts, Entertainments
Asians
Assets
Assistance
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Capital Expenditures
Child Care/Support
Commodity Flows
Communications
Consumer Income
County Business
Patterns
County/City
Government
TIGER
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Topologically Integrated Geographic
Encoding and Referencing system
Based on USGS topographic maps
but majorly augmented
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Contains no elevation data
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No copyright
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No street names
American Community
Survey
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Annual
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Long
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Representative – not comprehensive
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Master Address File for sample selection
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Wisconsin a forerunner
Pro’s and Con’s
of Secondary Data
Advantages
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Cheap
Timeliness
Access to
people/organizations
that we wouldn’t
have access to
otherwise
Less post-processing
Disadvantages
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Collection method
unknown
Lack of control
Data Vendors
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Remote Sensing
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Value adding to public data
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Utilities
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Market Research
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GIS Vendors
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University Extensions
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World Bank
Before YOU Purchase Data
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Accuracy
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Compatibility
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Lineage and metadata
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Who owns the copyright?