# Presentation: 174874

## Census 2000:

**Geographic Concepts & Products**** **

**Notes:**
This presentation is designed to give novice users a quick overview of the many geographic concepts and units that the Census Bureau uses in conducting the decennial census.

## Small-Area Geography Overview

**Notes:**
In census geography, we start with the most basic unit, the census block.  As you can see in this illustration, some of the more common census geographic units nest within the larger unit all the way up to the county level.  Now we’ll take a closer look at these individual units.

## Blocks

- Smallest units of data tabulation
- Cover the entire nation
- Do not cross census tracts or counties
- Generally bounded by visible features and legal boundaries
- Block numbers completely different from 1990
- Size: average about 100 people

**Notes:**
A block is defined as an area bounded on all sides by visible and/or invisible features shown on a map prepared by the U.S. Census Bureau. A block is the smallest geographic entity for which the Census Bureau tabulates decennial census data.
There are about 8,200,000 blocks delineated for Census 2000.
There has been a complete renumbering of blocks across the U.S.  One other major change is that the numbering has gone from a three-digit system to a four-digit system.  Water bodies were also assigned block numbers in Census 2000 for the first time.  

Speaker Note:  The Census Bureau used different “collection block numbers” for the precensus period and collection of data.  For delineation purposes different “tabulation block numbers” have been assigned. Block numbers for the precensus and census activities ignored many legal boundaries, whereas for data tabulation, the Census Bureau held every tabulation area boundary as a block boundary.  Basically, tabulation area boundaries are those block boundaries taken as a snapshot of geography on January 1, 2000.   

## Block Groups

- Groups of blocks sharing the same first digit
- Smallest areas for which sample data are available
- Size: optimally 1,500 people; range between 300 to 3,000

**Notes:**
A statistical subdivision of a census tract (or, prior to Census 2000, a block numbering area), a block group consists of a cluster of census blocks having the same first digit of their identifying numbers within that tract. 
For example, for Census 2000, BG 3 within a census tract includes all blocks numbered from 3000 to 3999. (A few BGs consist of a single block.) BGs generally contain between 300 and 3,000 people, with an optimum size of 1,500 people. 
The BG is the lowest-level geographic entity for which the U.S. Census Bureau tabulates sample data from a decennial census.

## Census Tracts

- Defined nationwide for the first time in Census 2000;
- Relatively homogeneous demographically;
- Relatively consistent boundaries over time;
- Approximately 65,000 census tracts in U.S.;
- Size: optimally 4,000 people; range between 1,000 and 8,000

**Notes:**
Census tracts are small, relatively permanent statistical subdivisions of a county or a statistically equivalent entity. Designed to be relatively homogeneous units with respect to population characteristics, economic status, and living conditions at the time they are established, census tracts generally contain between 1,000 and 8,000 people, with an optimum size of 4,000 people. Census tract boundaries are delineated with the intention of being stable over many decades, so they generally follow relatively permanent visible features. However, they may follow governmental unit boundaries and other invisible features in some instances; the boundary of a state or county is always a census tract boundary.
Census tracts are usually identified by a six-digit number composed of a four-digit basic number and a two-digit numeric suffix; for example, 8001.07.  This suffix (.07) indicates that the original tract, tract 8001, was split possibly into seven pieces as a result of population growth.  In some maps the census tract may be represented by a single digit number - in those cases the three leading zeroes were omitted for simplification.  However, all census tracts have 6 digits (first four and the last two after the decimal).  
In 1990 and previous censuses, the Census Bureau  created tract-like geographic units, called Block Numbering Areas or BNAs, outside of metropolitan areas.  BNAs were discontinued for Census 2000; instead, one or more census tracts were identified for every county and statistically equivalent entity. 

Speaker Notes: Census tracts are usually delineated for data presentation purposes by a local group of census data users or the geographic staff of a regional census center in accordance with U.S. Census Bureau guidelines. 

## Blocks, Block Groups, and Census Tracts

## Places

- Incorporated Places
- Census Designated Places

**Notes:**
There are two kinds of places in Census Bureau terminology: incorporated places and Census Designated Places (CDPs).  
A place is a concentration of population legally bounded as an incorporated place. A CDP is delineated for statistical purposes as a census designated place (in Puerto Rico, a comunidad or zona urbana).  These are created for the purpose of presenting census data for an area with a concentration of population, housing, and commercial structures that is identifiable by name, but is not within an incorporated place. For Census 2000, for the first time, CDPs did not need to meet a minimum population threshold to qualify for tabulation of census data.  
As you can see in this map taken from the American FactFinder, the boundaries of places - either incorporated or CDPs - do NOT necessarily correspond to census tracts, block groups or MCDs.  

Speaker note: CDP boundaries, which usually coincide with visible features or the boundary of an adjacent incorporated place or other legal entity boundary, have no legal status, nor do these places have officials elected to serve traditional municipal functions. CDPs usually are delineated in cooperation with state, Puerto Rico, Island Area, local, and tribal officials based on U.S. Census Bureau guidelines. 

## County Subdivisions

- Two types:
- Minor Civil Divisions (MCDs)
- Legally defined subcounty entities in 28 states, the District of Columbia, Puerto Rico, and the Island Areas.
- Census County Divisions (CCDs)
- Used to establish and maintain a set of subcounty units that have stable boundaries and recognizable names in 22 states.
- No minimum or maximum population guidelines

**Notes:**
A minor civil division (MCD) is the the primary governmental or administrative division of a county or statistically equivalent entity in many states and statistically equivalent entities. A minor civil division is created to govern or administer an area rather than a specific population.(ex. Town, Township, District)  The U.S. Census Bureau recognizes minor civil divisions in 28 states, the District of Columbia, Puerto Rico, and the Island Areas. 

A census county division (CCD) is a statistical subdivision of a county, delineated by the U.S. Census Bureau in cooperation with state and local government officials for data presentation purposes. A census county division usually represents one or more communities, trading centers or, in some instances, major land uses. The Census Bureau has established census county divisions in states that do not have minor civil divisions suitable for data presentation.  

Minor civil divisions and census county divisions together cover the entire country and provide a standard level of geography below the county. Minor civil divisions are more common in the East, while census county divisions are more common in the West.   

## County Subdivisions

- Census County Divisions in Taos County, NM

**Notes:**
In this map, we see Taos county in New Mexico.  This map displays the census county division using the green boundary that in some areas follows along the auburn-colored census tract boundaries.  In this case the census county division divides the county into 5 areas, while there are 6 census tracts visible in this county.  Again, census tracts may be altered for each census, while census county divisions and minor civil divisions are designed to be more stable and correspond to more obvious physical boundaries.  
Maps displaying minor civil division boundaries would be set up in essentially the same way, with township, town, or district boundaries replacing the census county division boundaries.  

## Counties and County Equivalents

- Counties in 48 states;
- Independent Cities in MD, MO, NV, and VA;
- Parishes in Louisiana;
- Cities, Boroughs, Municipality, Census Areas in Alaska;
- Municipios in Puerto Rico;
- Islands and Districts in American Samoa;
- Municipalities in the Northern Marianas;
- Islands in the Virgin Islands;
- District of Columbia and Guam each treated as a county equivalent

**Notes:**
EAST SLIDE VERSION
Counties are the primary subdivision of most states. A number of geographic entities are not legally designated as a county, but are recognized by the U.S. Census Bureau as equivalent to a county for data presentation purposes. These include the boroughs, city and boroughs, municipality, and census areas in Alaska; parishes in Louisiana; and cities that are independent of any county in Maryland, Missouri, Nevada, and Virginia.  Because they contain no primary legal divisions, the Census Bureau treats the District of Columbia and Guam each as equivalent to a county (as well as equivalent to a state) for data presentation purposes. 
The map on this slide illustrates the independent city of Baltimore in Maryland.  Notice that it is entirely surrounded by counties, in this case Baltimore County and Anne Arundel County.

Speaker Notes:  Other division recognized as county equivalents: municipios in Puerto Rico, districts and islands in American Samoa, municipalities in the Northern Mariana Islands, and islands in the Virgin Islands.  
A county is a minor civil division in American Samoa. 
City and Borough in Alaska: A legally established geographic entity in Alaska, which the U.S. Census Bureau treats as the statistical equivalent of a county in other states; also, in Alaska, a type of incorporated place. This designation is new for Census 2000.

## Other Geographic Areas

- Large Geographic Areas
- U.S. 	- Metropolitan Areas (for Census 2000; Metropolitan and Micropolitan Statistical Areas as of June 2003)
- Regions	- Urban Areas
- Divisions 	- American Indian Reservations
- States 	- Alaska Native Areas
- 	- Hawaiian Home Land Areas
- Special Geographic Areas
-      Zip Code Tabulation Areas (ZCTAs)
-      Public Use Microdata Areas (PUMAs)

**Notes:**
There are also larger geographic levels for which data are available; some of these are outside of any geographic hierarchy.  

## Census Regions and Divisions

**Notes:**
Everyone is familiar with the 50 States.  The District of Columbia and the Commonwealth of Puerto Rico are treated as state equivalents.  
In some Census 2000 and Economic Census products you will see data for regions and divisions.  The Census Bureau divides the Nation into four regions and nine divisions, composed of groups of states.  
Here we see a map displaying the Census regions and divisions of the United States. 
The South region is divided into the South Atlantic, East South Central, and West South Central divisions.
The Northeast region is divided into New England and the Middle Atlantic divisions.  
The Midwest region is divided into the West North Central and East North Central divisions.
The West region is divided into the Mountain and Pacific divisions.

Now we’ll take a look at Metropolitan Areas.

## Metropolitan Areas (MAs)

- Defined by the Office of Management and Budget (OMB)
- Counties are “building blocks” except in New England where cities and towns are used
- Contain large population nucleus
- High socioeconomic integration

**Notes:**
The general concept of a Metropolitan Area is that of a core area containing a large population nucleus, together with adjacent communities having a high degree of economic and social integration with that core.
Currently defined Metropolitan Areas are based on application of 1990 standards to 1990 decennial census data and to subsequent Census Bureau population estimates and special census data.
The collective term ”Metropolitan Area" (MA) became effective in 1990. Metropolitan Areas include Metropolitan Statistical Areas (MSAs), Consolidated Metropolitan Statistical Areas (CMSAs), and Primary Metropolitan Statistical Areas (PMSAs). 

## Metropolitan Areas: Three Types

- Metropolitan Statistical Area (MSA): Based around a city of 50,000 or more inhabitants, or a Census-defined urbanized area and a total metropolitan population of at least 100,000 (75,000 in New England)
- Consolidated Metropolitan Statistical Area (CMSA): Meets MSA standards and population > 1 million, meets additional criteria for subdividing, and local opinion supports component areas
- Primary Metropolitan Statistical Area (PMSA): Components that make up a CMSA
- Note: New standards adopted in 2000 and applied with Census 2000 data.  New area definitions announced in June 2003.

**Notes:**
Under Metropolitan Area standards, the county (or counties) that contains the largest city becomes the "central county" (counties), along with any adjacent counties that have at least 50 percent of their population in the urbanized area surrounding the largest city. Additional "outlying counties" are included in the MA if they meet specified requirements of commuting to the central counties and other selected requirements of metropolitan character (such as population density and percent urban). In New England, the MAs are defined in terms of cities and towns rather than counties.
Metropolitan Statistical Areas (MSAs) are generally smaller metropolitan areas under 1,000,000 in population.  
Consolidated Metropolitan Statistical Areas (CMSAs) are large metropolitan areas such as NY, Chicago, LA, etc. that have over 1,000,000 in population.  Within CMSAs are the smaller components called Primary Metropolitan Statistical Areas (PMSAs).  For example in the Washington-Baltimore CMSA, there are three PMSAs: Washington, Baltimore, and Hagerstown. 
As of the June 30, 1999 OMB announcement detailing the 1990 MA standards, there were 258 MSAs, and 18 CMSAs comprising 73 PMSAs in the United States. In addition, there were 3 MSAs, 1 CMSA, and 3 PMSAs in Puerto Rico. 
The Office of Management and Budget (OMB) announced revised standards for metropolitan statistical areas, and a new type of entity called a micropolitan statistical area, in the Federal Register on December 27, 2000. OMB announced definitions of metropolitan and micropolitan statistical areas, metropolitan divisions, combined statistical areas, New England city and town areas (NECTAs), NECTA divisions, and combined NECTAs in June 2003.  OMB also announced updates to the classification in December 2003.  The Census 2000 data products present information for the metropolitan areas and central cities announced by the OMB on June 30, 1999, and therefore are in effect on Census Day, April 1, 2000; these entities reflect the 1990 metropolitan area standards. 

## Washington-Baltimore, CMSA

## Metropolitan and Micropolitan Statistical Areas

- Terms have changed, but the basic concept has remained the same:
- Core area containing a substantial population nucleus, together with adjacent communities having a high degree of integration with the core.
- New Terms:
- Core Based Statistical Area (CBSA)
- Micropolitan Statistical Area
- Metropolitan Division
- Combined Statistical Area
- New England City and Town Area
- Principal City

**Notes:**
The 2000 standards provide that each CBSA must contain at least one urban area of 10,000 or more population. Each metropolitan statistical area must have at least one urbanized area of 50,000 or more inhabitants. Each micropolitan statistical area must have at least one urban cluster of at least 10,000 but less than 50,000 population.
Under the standards, the county (or counties) in which at least 50 percent of the population resides within urban areas of 10,000 or more population, or that contain at least 5,000 people residing within a single urban area of 10,000 or more population, is identified as a "central county" (counties). Additional "outlying counties" are included in the CBSA if they meet specified requirements of commuting to or from the central counties. Counties or equivalent entities form the geographic "building blocks" for metropolitan and micropolitan statistical areas throughout the U.S. and Puerto Rico.
If specified criteria are met, a metropolitan statistical area containing a single core with a population of 2.5 million or more may be subdivided to form smaller groupings of counties referred to as "metropolitan divisions."
As of June 6, 2000, there are 362 metropolitan statistical areas and 560 micropolitan statistical areas in the U.S. In addition, there are 8 metropolitan statistical areas and 5 micropolitan statistical areas in Puerto Rico.
Principal Cities and Metropolitan and Micropolitan Statistical Area Titles
The largest city in each metropolitan or micropolitan statistical area is designated a "principal city." Additional cities qualify if specified requirements are met concerning population size and employment. The title of each metropolitan or micropolitan statistical area consists of the names of up to three of its principal cities and the name of each state into which the metropolitan or micropolitan statistical area extends. Titles of metropolitan divisions also typically are based on principal city names but in certain cases consist of county names.

## Core Based Statistical Areas (as of December 2003)

- 369 Metropolitan Statistical Areas
- 		361 in the United States (1,090 Counties)
- 		    8 in Puerto Rico (68 municipios)
- 11 Metropolitan Statistical Areas subdivided into 29 Metropolitan Divisions
- 578 Micropolitan Statistical Areas
- 		573 in the United States (690 counties)
- 		    5 in Puerto Rico (5 municipios)

## Urbanized Areas

- Densely settled areas with population of at least 50,000
- Geographic core of block groups or blocks that have a population density of at least 1,000 people per square mile
- Area definitions announced in March 2002 with updates in August and November 2002
- www.census.gov/geo/www/ua/ua_2k.html

**Notes:**
The Census Bureau is currently reviewing its criteria for urban/rural delineations and will be announcing the official decision in the 2nd quarter of 2002.  
An urbanized area (UA) is a densely settled area that has a census population of at least 50,000. At least 35,000 people in an urbanized area must live in territory that is not part of one or more military reservations, or it is classified as an urban cluster. A UA generally consists of a geographic core of block groups or blocks that have a population density of at least 1,000 people per square mile, and adjacent block groups and blocks with at least 500 people per square mile. A UA may consist of all or part of one or more incorporated places and/or census designated places, and may include area adjacent to the place(s).
UAs and MAs are not synonymous. Urbanized areas are based on blocks and block groups.  Metropolitan areas include complete counties.  
For Census 2000, UA delineations constitute a zero-based approach that requires no grandfathering of UA boundaries from the 1990 census.  In a nutshell the new delineations have more stringent density requirements and less restrictive extended place criteria.

## Orlando, FL Urbanized Area

## ZIP Code Tabulation Areas (ZCTAs)

- Approximate area representations of USPS ZIP Code service areas
- Based on Census 2000 blocks
- To address difficulties in mapping USPS ZIP Codes
- May represent either a five or three-digit USPS ZIP Code

**Notes:**
Another new aspect of geography for Census 2000 is the ZIP Code Tabulation Area (ZCTA).  This is a new statistical area that the Census Bureau has created to address the problems associated with tabulating data by ZIP Codes.  They are generalized representations of USPS ZIP Code areas.  Since ZIP Codes are tools for delivering mail and were never intended to provide the basis for statistical tabulations, they are often not appropriate for that use.  ZIP Codes are usually just collections of streets representing a carrier route. What complicates matters is that they can be assigned to just one building, or even to a single company within a building and they are solely designed to get the mail delivered.

Zip Code Tabulation Areas can represent either five or three-digit Postal Service ZIP Codes.  There are no ZCTAs for the nine-digit ZIP Codes.

## Creating ZIP Code Tabulation Areas

- Determine the majority ZIP Code for each census block with addresses.

**Notes:**
To be able to provide statistical data by ZIP Codes, the Census Bureau has created the ZIP Code Tabulation Area or ZCTA to be as close an approximation to actual ZIP Code coverage as possible but also having the characteristics of other statistical areas, such as definable boundaries.  The Census Bureau uses the addresses in its Topologically Integrated Geographic Encoding and Referencing System or TIGER database and Master Address File database to determine the areas covered by each ZIP Code and uses that information to interpolate boundaries for these areas as they relate to Census 2000 blocks. This means that the Census Bureau will create Zip Code Tabulation Areas by grouping whole census blocks.  The ZIP Code used by the majority of addresses in a given block will determine the ZIP Code Tabulation Area code for that block.  While there is no legal or operational requirement for the Postal Service to abide by these boundaries the Census Bureau believes that ZIP Code Tabulation Areas will closely follow actual ZIP Code coverage.  Also note that P.O. Boxes and rural routes will not have accompanying ZIP Code Tabulation Areas.

## Public Use Microdata Areas (PUMAs)

- Geographic entity for extracts of raw data from a small sample of confidentiality-screened, long-form census records
- PUMA - Minimum population of 100,000, cannot cross a state line (5-percent long-form records sample)
- Super PUMAs - Aggregated PUMAs with a minimum population of 400,000 (1-percent long-form records sample)
- Available Now in CD-ROM format only

**Notes:**
Public Use Microdata Areas (PUMAs) are geographic entities for which the U.S. Census Bureau provides specially selected extracts of raw data from a small sample of long-form census records.  All personal identifying information has been removed from these records.  The extract files are referred to as public use microdata samples (PUMS). PUMAs are composed of counties or groups of counties.
Public Use Microdata Areas must have a minimum census population of 100,000 and unlike 1990 cannot cross a state line.  A 5-percent sample of the long-form records is extracted and presented in state files.  Super-PUMAs, areas of 400,000 population, are combinations of PUMAs and represent the areas for which the Census Bureau provides a 1-percent file.
(Data users can use these files to create their own statistical tabulations and data summaries.)

Another new wrinkle for Census 2000 Public Use Microdata Areas is that the 5-percent PUMAs must nest within the 1-percent PUMAs whereas in 1990 the different sets could cover different areas.

## Public Use Microdata Areas

## Hierarchy - Summary File 1: State File Summary Levels

- State
- 	County
- 		Place (or place part)
- 		    Census tract
- 			  Block group
-                		Block
- State portion of American Indian and Alaska Native Area (with trust lands and with no trust lands) and Hawaiian home land

**Notes:**
Using the example of the Census Bureau’s Summary File 1 (SF 1), this slide illustrates how attention must be paid to what levels of geography are included in different data products.    
Summary File 1 is released as individual files for each of the 50 states, the District of Columbia, and Puerto Rico; and for the United States. The tables are identical for all files, but the geographic coverage differs.

Summary File 1 for states, the District of Columbia, and Puerto Rico provides data for these areas and their subareas in hierarchical sequence down to the block level (census tract level for some tables). The file structure includes, but is not limited to the geographic entities shown on the slide: state, county, county subdivision, place (or place part), census tract, block group and block.
SF 1 for states also has summarized data for the following geographic areas; Place, Census tract, Block group, Congressional District (106th Congress), Consolidated city, Metropolitan area and ZIP Code tabulation area (ZCTA).

## Unique Geographic Identifiers

- Federal Information Processing Standards (FIPS) Codes
- _Area__	_	_Name_			_2000 FIPS_
- State	North Carolina 		     37
- County	Transylvania		     175
- Place	Wilmington 		     74440

**Notes:**
To help users process information on CD-ROM, DVD, and to uniquely identify geographic areas, the Census Bureau uses a series of geographic identifiers which are generally numeric codes established by the National Institute of Standards, and known as FIPS or Federal Information Processing Standards codes.
In Census Bureau data products, you will find FIPS codes for higher level geographic units such as states, counties, places, congressional districts, etc.
The Census Bureau establishes its own set of codes as, for example, in the case of census tracts or blocks if there is no FIPS code for the geographic entity or if the FIPS codes is not adequate for data presentation.  
These codes are used for each unique geography to allow users to link their own databases to the census data.

Speaker Note: (A census code exists for each state, but was not assigned in alphabetical sequence and serves to organize the states by census region and census division.)

## Geographic Products:The TIGER Data Base

**T****opologically **
**I****ntegrated **
**G****eographic   **
**E****ncoding and**
**R****eferencing**

** **The source of ALL census 		geographic products

**Notes:**
TIGER is an acronym for the Topologically Integrated Geographic Encoding and Referencing (System or database). It is a digital (computer-readable) geographic database that automates the mapping and related geographic activities required to support the U.S. Census Bureau's census and survey programs.  All geographic products are derived from the TIGER database.

The content of the TIGER database is undergoing continuous updates, and is made available to the public through a variety of TIGER/Line® files.

## Redistricting Census 2000 TIGER/Line Files
First View of 2000 Block Boundaries
Census 2000 TIGER/Line Files
ZIPCode Tabulation Area Boundaries
Final Census 2000 Address Information
UA Census 2000 TIGER/Line Files
New additions: Urbanized Areas (UA) and Public Use Microdata Areas (PUMA)
Available Now: www.census.gov/geo/www/tiger/

- First View of 2000 Block Boundaries
- Census 2000 TIGER/Line Files
- ZIPCode Tabulation Area Boundaries
- Final Census 2000 Address Information
- UA Census 2000 TIGER/Line Files
- New additions: Urbanized Areas (UA) and Public Use Microdata Areas (PUMA)
- Available Now: www.census.gov/geo/www/tiger/

**TIGER/Line Files**

**Notes:**
The most current release of TIGER/Line Files is the Redistricting Census 2000 TIGER/Line Files.  This version of the TIGER/Line Files contains all the Census 2000 entities EXCEPT FOR the ZIP Code Tabulation Areas (ZCTAs), nor do they contain the updated final Census 2000 address ranges information.  In a nutshell, users will need a mapping software package to convert TIGER/Line Files into maps.  
Speaker Note: The Redistricting Census 2000 TIGER/Line Files cover all counties, parishes, boroughs, census geographic areas and equivalent entities for each state, the District of Columbia, and Puerto Rico. The Redistricting Census 2000 TIGER/Line Files will NOT include files for American Samoa, Guam, the Northern Mariana Islands, the Minor Outlying Areas (Midway), and the U.S. Virgin  Islands because these areas do not redistrict for congressional apportionment.]

The Census 2000 TIGER/Line Files, scheduled for release in the second quarter of 2001, will include the full files for all areas, as well as the ZIP Code Tabulation Area information and the updated Census 2000 address ranges.  

Once available, TIGER/Line files are posted to the internet for download. The county files are stored in compressed format and are compatible with PK Ware's PK Zip software (which is available for free off the internet at www.pkunzip.com). The Census Bureau is providing the TIGER/Line files in ASCII text format only and the data are NOT in the form of map images.

## Relationship Files

- Relationships (1:1, 1:n, n:1)
**Not Equivalency Files (use TIGER/Line)**
- Census Tracts: 1990-2000
**Similar to 1990 product**
- Blocks 1990 - 2000
**1990 Tabulation to 2000 Collection**
**1990 Tabulation to 2000 Tabulation**
**2000 Collection to 2000 Tabulation**
- Available now on the Internet:
-     www.census.gov/geo/www/relate/relfile.html

**Notes:**
In addition to the TIGER/Line files, we are planning to produce several other electronic products.  The first is two sets of relationship (formerly called comparability) files.  These files help users who are comparing 1990 and 2000 Census data for small areas (census tracts and blocks) since these boundaries can change from one census to the next.
For each 1990 census tract or block, a relationship file provides a summary listing of which tracts or blocks cover all or some of the same area in 2000.  

The very detailed equivalency information showing  which block or tract a given piece of land  belonged to in 1990 and 2000 can be derived from the information in the TIGER/Line files.

Media: CD-Rom  	Availability:  3rd Quarter 2001
Speaker Note:
Tabulation blocks vs collection blocks in Census 2000: To improve operational efficiency and geographic identifications, the U.S. Census Bureau has introduced different numbering systems for tabulation blocks used in decennial census data products and for collection blocks used in administering the census. (In 1990, there generally was a single numbering system.) Collection block numbers are available only in the TIGER/Line data products; the U.S. Census Bureau does not tabulate data for collection blocks. 

## Boundary Files

- For most levels of tabulation geography
- File Formats:
- ArcView shapefiles (*.shp)
- ARC/INFO Export (*.e00)
- ARC/INFO Ungenerate (ASCII)
- Available Now on the Internet: www.census.gov/geo/www/cob/index.html

**Boundary Files**

**Notes:**
Cartographic boundary files are generalized boundary files appropriate for small scale thematic mapping.  The files are available for most levels of census geography.  
The lowest level geography that will be available is by census block group in June 2001.  PUMAs, MAs, UAs and Congressional Districts will be added as available.  These files can be found on the internet in various different formats: ARC/INFO Export (.e00), Arcview Shape (.shp), and ASCII.

## Printed by:
The Census Bureau
Census partners 
Other various commercial sources
Selected printed reports/maps
May be available through 
State Data Center - www.census.gov/sdc/www
Census Regional Office - www.census.gov/field/www

- The Census Bureau
- Census partners
- Other various commercial sources
- Selected printed reports/maps
- May be available through
- State Data Center - www.census.gov/sdc/www
- Census Regional Office - www.census.gov/field/www

- On-Demand Paper Maps

**Notes:**
To get an idea of how much it will cost you for on-demand paper maps: 
Through our Customer Services Center (CSC), the Census Tract Outline Maps are sold only in a state or county package.  These maps sheets measure: 36 by 33 inches, each map sheet is $5, there is a  $25 minimum order fee, and orders require 5 to 10 business days to process.
It may be more cost-efficient for the individual user to piece together free, internet-posted PDF files printed out to a PC rather than purchase maps. 

## Questions About Geographic Products?

- E-mail:  geography@census.gov
- URL:  www.census.gov
- Product information: 301-763-INFO
- Geographic questions: 301-763-1128