1. Lecture 07 Secondary Data
GTECH 361
Lecture 07 Secondary Data

2. Geodatabase Topology
Rule-based

3. Geometric Networks

4. Editing With Topology

5. Relationship Classes

6. Types of Geodatabases
Personal GDB
Enterprise GDB

7. Inside the Geodatabase

8. Now to the Session Proper
Secondary data sources
US Census
Geo data portal

9. Why Secondary Data?
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

10. Unofficial Secondary Data Sources
Private research results
Research reports, research papers, textbooks
Opinion polls
Market research
On-line databases
Anecdotal/hearsay

11. Official Secondary Data Sources
Agriculture
Business/Industry
Crime
Education
Finance
Energy
Environment
Health
Transport
Weather

12. Agriculture
USDA
FAO
Farm Bureau Federation
Babcock

13. Business / Industry STAT-USA/Internet (US Dep. of Commerce, not free)
Consumer Expenditure Surveys (Bureau of Labor Statistics)
Internal Revenue Service

14. Crime Bureau of Justice Statistics FBI
Crime & Justice Electronic Data Abstracts

15. Education National Center for Education Statistics
School District Data Book (ORST)
National Science Foundation
UNESCO

16. Environment EPA Envirofacts EPA EnviroMapper ScoreCard Right To Know
Facility Information
Hazardous Waste Data
Superfund
Toxics Releases Inventory
Water Discharge Permits
ScoreCard
Right To Know

17. Health National Center for Health Statistics (CDC)
Social Security Administration

18. Geophysical NOAA USGS US Forest Service Soil Conservation Service
Dep. of Natural Resources (DNR)
Dep. of Conservation

19. Transportation Department of Transportation
Bureau of Transportation Statistics
State Highway Departments (CA, TX)
Regional Transport Authorities

20. Census Structure Timing Population Organization Analysis Presentation
Geographical Hierarchy
Variables

21. Historical Context
Article I, Section 2 of the U.S. Constitution adopted in 1787 approved that Representatives and Taxes shall be apportioned among the states according to each states population.
Enumeration (to ascertain the number of: count) shall be made within every subsequent term of 10 years

22. Historical Context
The first Census of Population was conducted in 1790, it counted 3.9 million people and increased representation in the House to 105.
As the Nation’s needs and interests became more complex statistics were added to help people understand what the raw numbers meant.

23. What is Collected?
In 1954 Title 13 of the United States Code brought together the laws under which the Census Bureau operates
This included a law requiring the following Censuses to be conducted:
Population, housing, manufacturers, mineral industries, other businesses, construction, transportation, and governments at stated intervals

24. Confidentiality
The sole purpose of the censuses is to secure general statistical information. Replies are obtained from individuals and establishments only to enable the compilation of these general statistics
By law, no one is permitted to reveal identifiable information
Before any information is published it is checked to make certain that no individual, household or organization can be identified

25. Confidentiality
The individual forms filled out are closed to public viewing for 72 years
The Freedom of Information Act does not apply to identifiable census data

26. Census 2000 Forms 2 main types, a short form and a long form
The short form asks 7 questions
83% of households received the short form
The long form covers 34 subjects
1 in 6 households received the long form
The long form took approximately 38(?!) minutes to complete

27. Why Two Forms? The short form The long form
The data from the long form is considered to be representative of all the people in the “neighborhood” and is extrapolated into sample data
The data from the short form is considered to count 100% of the population

28. Dealing with Census Data
The main way to tackle census data is by:
Geographic extent of the area you are interested in and
Variables or subjects
The key is to combine the two

29. Census Geography It is confusing! Changes over time
Some levels are based on population numbers
Do not compare oranges to apples!!

30. Census Geographic Areas
States, DC and Puerto Rico
Counties
Cities, towns, and townships
Census tracts (roughly 4000 people, neighborhood sized areas)
Block groups (groups of census blocks, generally containing 800 to 1,000 people)
Blocks (9 million, covering entire US, not all data is summarized to this level)
Congressional districts
American Indian and Alaska Native Areas

31. Census Geographical Hierarchy

32. Metropolitan Areas

33. Census Geography It is confusing! Changes over time
Some levels are based on population numbers
Do not compare oranges to apples!!

34. Census Household Variables
Number of persons
Age and gender
Race
Language
Income and poverty
Education
Employment
Citizenship
Vehicles for commute
Disability
Homeownership status
Vacancy
Rent and value of housing
Age and type of structure
Plumbing and Kitchen
Heating

35. Examples of Census Variables
Accommodations
Agriculture
Alaska Natives
Arts, Entertainments
Asians
Assets
Assistance
Capital Expenditures
Child Care/Support
Commodity Flows
Communications
Consumer Income
County Business Patterns
County/City Government

36. The Concept of Race Not based on any scientific definition
Prior to Census 2000 only allowed 1 choice
Census 2000 allowed the following choices for Race:
White
Black, African American
American Indian or Alaska Native (tribe was requested)
Asian Indian, Japanese, Chinese, Filipino, Hawaiian, Korean, Vietnamese, Guamanian or Chamorro
Samoan
Or to be written in if none of these apply

37. Ethnic Origin
The Hispanic population is considered an ethnic group according the the Census Bureau
In Census 2000 choices for Hispanic origin or descent were:
Mexican
Mexican American
Puerto Rican
Cuban
Or Other Spanish/Hispanic/Latino

38. Race/Ethnic Origin
The concept of race separate from Hispanic origin has been confusing Census users for years
The thing to remember is that while a person may be of Hispanic origin, they also are white, black, asian-pacific islander, or other
It’s the same concept of being white and of german ethnicity

39. Multiracial Categories Controversy
Until 1970 the Census Bureau enumerator decided people’s race for them, sometimes by inquiring, often by simply looking
Since 1970 people could choose only 1 race to describe themselves
Census 2000 allowed people to choose any number of races
Over 7 million people marked more than one race to describe themselves
This number is less than 3 percent of the total population but has huge impacts in a number of ways

40. Native Americans
If one counts only those who checked American Indian alone, 2.5 million
If one counts those whites and blacks who think they have a little Indian blood, and checked it in addition to white or black categories, 4.1 million
That is an increase of nearly 65%
Should the Federal Government increase services for Native Americans by 65%?

41. Statistical Problems
The Census Bureau’s racial percentages now add up to well over 100
No one can reliably compare 1990 or earlier data to 2000 data

42. TIGER
Topologically Integrated Geographic Encoding and Referencing system
Based on USGS topographic maps but majorly augmented
Contains no elevation data
No copyright
No attribute data!

43. American Community Survey
Annual
Long
Representative – not comprehensive
Master Address File for sample selection
Wisconsin a forerunner

44. Pro’s and Con’s of Secondary Data
Disadvantages
Collection method unknown
Lack of control
Advantages
Cheap
Timeliness
Access to people/organizations that we wouldn’t have access to otherwise
Less post-processing

45. Geoinformation Portals
Public data (mostly federal)
Public and private data (sometimes costly)

46. Data Vendors Remote Sensing Value adding to public data Utilities
Market Research
GIS Vendors
University Extensions
World Bank

47. Before YOU Purchase Data
Accuracy
Compatibility
Lineage and metadata
Who owns the copyright?