CONTENTS
Data
Products
Geographic
Products
Other
Census Bureau Resources
Reference
Materials
Sources of
Assistance
The 1990 census data products, being released during 1991-94, are available in a variety of new and traditional media. The Census Bureau has increased the product options available to data users in an effort to meet a variety of requirements and maximize the usefulness of the data. For example, laser discs, called CD-ROM (compact disc--read- only memory), are a new data delivery medium. The Census Bureau also has expanded services and sources of assistance available to data users. For example, the State Data Center Program has been expanded to include over 1,400 organizations to pro- vide data and services to the public. This appendix provides a detailed introduction to the 1990 census data products and related materials, such as maps and reference publications. It concludes by describing sources of assistance and other Census Bureau data available to the public.
Printed reports and computer tape files traditionally are the most
widely used products. The Census Bureau also offers data on microfiche,
on CD-ROM laser discs, and through its online service, CENDATA(TM).
These various products are described below. For information about
prices and how to order, write or call Customer Services. (See the
"Sources of Assistance" section for the address and phone number.)
The data products present statistics about the subjects covered in
the 1990 census questionnaires. These subjects are listed in figure 1.
As the figure shows, there are 100-percent subjects (those covered in
questions asked of everyone or about every housing unit) and sample
subjects (those covered in questions asked at about one out of every six
housing units). Generally, a data product presents either 100-percent
data prepared by tabulating the responses to the 100-percent questions
from all questionnaires, or sample data prepared by tabulating only the
responses to the 100-percent and sample questions from the "long-form"
questionnaires. Two report series, 1990 CPH-3 and 1990 CPH-4 (see
figure 2), present both 100-percent and sample data.
Printed Reports
Printed reports are the most convenient and readily available source
of data for most census users. The Census Bureau releases the reports
in several series (see figure 2) that are grouped under three broad
titles: 1990 Census of Population and Housing (1990 CPH), 1990 Census
of Population (1990 CP), and 1990 Census of Housing (1990 CH). There
also are reports, not reflected in figure 2, for the outlying areas of
the Pacific. The reports are sold by the Superintendent of Documents,
U.S. Government Printing Office. (See the "Sources of Assistance"
section for the address and phone number.)
In several series, there are separate reports for each State. The
geographic coverage of the State reports is listed in figure 2. The
United States summaries for these report series contain, for the most
part, data for the United States, regions, divisions, States, metro-
politan areas (MA's), urbanized areas (UA's), counties, American Indian
and Alaska Native areas, places with 10,000 or more persons, and other
large substate areas (for example, county subdivisions, such as towns
and townships, with 10,000 or more persons in selected States).
Report series that present data for small areas, such as census
tracts, contain limited subject-matter detail (for example, counts of
people by age ranges--under 5 years, 5 to 9 years, etc.--rather than by
single years). Report series that include greater amounts of subject-
matter detail include less geographic detail.
Computer Tape Files
The Census Bureau provides more data on tape and other machine-readable
products than in printed reports. These products are sold by the Census
Bureau's Customer Services. There are several general types of data
files released on computer tape (available on both reels and cartridges).
They are introduced below, and more information is presented in figures 3
and 4, pages F-12 through F-14.
Public Law 94-171 Data--This data file presents the counts designed and
formatted for use in legislative redistricting. These counts also are
available on CD-ROM and paper listings. Excerpts are available on
CENDATA (TM). The counts, for areas as small as blocks, census tracts,
and voting districts, include totals for population, race groups, persons
of Hispanic origin, population 18 years and over, and housing units. (See
figure 4.)
Summary Tape Files (STF's)-- These computer tape files provide statistics
with greater subject-matter detail than printed reports. They also
present statistics for some types of areas, such as block groups and
blocks, that are not included in the reports. (See figure 3.)
Here are some important features of STF's:
Each STF presents a particular set of data tables for specific types
of geographic areas.
Each STF has three or more file types (indicated by a letter suffix
attached to the STF number) that differ in the geographic levels
reported, but contain the same data detail.
STF's 1 and 2 contain 100-percent data, and STF's 3 and 4 offer
sample data.
STF's 1 and 3 report on smaller areas and offer less data detail
than STF's 2 and 4.
STF's 1 through 4 offer greater data detail than the 1980 STF's 1
through 4.
Subject Summary Tape Files (SSTF's)--These files are the source of the
subject reports and provide greater subject-matter detail than the STF's.
They present data for the United States, regions, and divisions, and, in
some cases, also for States, counties, and large cities. (See figure 4.)
Public Use Microdata Sample (PUMS) Files--These computer tape files (see
figure 4) contain data from samples of long-form housing-unit records
("microdata") for large geographic areas. Each sample housing-unit record
includes essentially all the 1990 census data collected about each person
in a sample household and the characteristics of the housing unit. Infor-
mation that could be used to identify an individual or a housing unit is
not included in the file.
Microdata files enable users to prepare customized tabulations and
cross-tabulations of most items on the census questionnaire. There are
two standard PUMS files:
A file presenting a 5-percent sample of housing units in which each
household record includes codes to let the user know in what area,
such as a group of counties, a single county, or a place, the
household is located. Each area identified must have a population of
at least 100,000 and boundaries that do not cross State lines.
A file presenting a 1-percent sample of housing units. Its household
records include codes associating them with MA's and other large
areas, the boundaries of which may cross State lines. (For the 1980
census, there were two files with 1-percent samples. The 1-percent
sample showing data for selected urbanized areas and other large
areas will not be produced for the 1990 census.)
There also is a special 3-percent "elderly" file with the same
geography as the 5-percent sample. Included are households with at
least one person age 60 or more and all members of those households.
Other Special Computer Tape Files--Other files include the Census/Equal
Employment Opportunity (EEO) File and the County-to-County Migration
File. (See figure 4.) The Census Bureau may prepare additional special
files.
Microfiche
All printed reports are offered on microfiche from Customer Services
soon after they are published. Plans to prepare microfiche versions of
selected other products were canceled, so that more products could be
produced on CD-ROM.
Compact Disc--Read-Only Memory (CD-ROM)
For the 1990 census, the Public Law (P.L.) 94-171 file; an extract
of STF 1B that presents selected statistics for blocks; and STF's 1A,
1C, 3A, 3B, and 3C are also available on CD-ROM. The Census Bureau also
offers on CD-ROM: PUMS Files, SSTF's, Census EEO File, and County-to-
County Migration File.
Also, other files available on tape can be transferred to CD-ROM by special
arrangement with Customer Services (301-457-4100). The cost for such CD's
is the same as the cost for the tape files, and, like the tapes, they do
not include software. (One 4 3/4-inch CD-ROM, a type of optical or laser
disc, can hold the contents of approximately 1,600 flexible diskettes, or
three or four high-density computer tapes.)
Online Information Systems
The Census Bureau began CENDATA (TM), its online information service,
in 1984. CENDATA (TM) is accessible through two information vendors,
CompuServe and DIALOG. A number of Census Bureau reports, in whole or
in part, are offered online. For the 1990 census, CENDATA (TM) provides
up-to-date information about the availability of data products and
carries selections of State, county, MA, and place data from the P.L.
94-171 tape file and STF's 1 and 3. CENDATA also offers the entire
Census EEO File.
Special Tabulations
These products are for users who require unique tabulations that are
not included in standard products; for example, information for locally
defined geographic areas. Users also can order special microdata files.
Any data that the Census Bureau provides in these products are subject to
the same standards applied to other data to ensure that confidential
individual information is not revealed.
The cost of preparing special tabulations must be paid by the users who
request them. Users should rely on standard reports, tapes, microfiche, or
user-defined area tabulations whenever possible, since special tabulations
tend to be substantially more expensive and take time to arrange and
produce. (Contacts for more information are given in the "Sources of
Assistance" section.)
Maps Census Bureau maps are necessary for virtually all uses of small-area 1990 census data. They are needed to locate the specific geographic areas for which the census provides data and to study the spatial relationship of the data for analytic purposes. The Census Bureau prepares a variety of 1990 census maps. Among the most useful are these series: County Block Maps--These maps show census blocks and their numbers; boundaries for statistical and governmental entities, such as census tracts and places; and physical features. The P.L. 94-171 version of these maps also shows voting district boundaries in those States that furnished them. The maps are prepared on electrostatic plotters by county (or equivalent entity) with one or more map sheets each, depending on the size and shape of the area and the density of the block pattern. An average county requires 20 map sheets. The maps may be purchased from Customer Services. County Subdivision Outline Maps--Maps in this State-based series present the boundaries of the counties, county subdivisions, places, American Indian and Alaska Native areas (including off-reservation trust lands), tribal designated statistical areas, and tribal jurisdiction statistical areas. Electrostatic-plotter copies are available for purchase from Customer Services. Also, they appear on multiple page-size sheets in the State reports of these series: 1990 CPH-1, 1990 CPH-2, 1990 CPH-5, 1990 CP-1, 1990 CP-2, 1990 CH-1, and 1990 CH-2. Census Tract/Block Numbering Area (BNA) Outline Maps--Maps in this county-based series depict census tract or BNA boundaries and numbers, and the features underlying the boundaries. They also show governmental units in relation to the census tracts/BNA's. The Superintendent of Documents sells printed copies. Urbanized Area Outline/Boundary Maps--Maps in this urbanized area-based series depict the boundaries of the urbanized area and the features underlying the boundaries. They also show the boundaries for American Indian and Alaska Native areas (AIANA's), States, counties, county sub- divisions (MCD's/CCD's), places (incorporated and census designated), the map series subject area, and selected base features and their names at a small scale. Electrostatic-plotter copies are available for purchase from Customer Services. Also, they appear on multiple page-size sheets in the State reports of the 1990 CPH-2 series and the Supplementary Report, 1990 CPH-S-1-2, Urbanized Areas of the United States and Puerto Rico: 1990. Voting District Outline Maps--Maps in this county-based series depict voting district boundaries (for those counties for which States furnished boundary information) and the features underlying the boundaries. They also show governmental unit boundaries in relation to the voting districts. They are prepared on electrostatic plotters and sold by Customer Services. Geographic Publications The Geographic Identification Code Scheme report in the 1990 CPH-R series will not be printed. Persons interested in this report are encouraged to use the TIGER/GICS(TM) tape file (which also will be available on CD-ROM) described below. Listings similar to the tables that would have been included in the report may be offered. Contact Customer Services, Data User Services Division, Bureau of the Census, Washington, DC 20233, telephone 301-457-4100. The Congressional District Atlas, 103rd Congress of the United States is a two-volume, 1,200-page atlas depicting the boundaries and number of the districts for the 103rd Congress as defined following the 1990 decennial census. This is the first Congress defined following the 1990 decennial census and, therefore, illustrates the most significant changes of the decade, including the reapportionment of the U.S. House of Representatives. Congressional district boundaries following govern- mental unit boundaries such as an incorporated place of a minor civil division, are illustrated using symbology identified in the map legend. Wherever possible, features used as congressional district boundaries are identified by their feature name or their feature type. The Census Bureau may produce subsequent atlases if court ordered or State mandated redistricting creates new congressional district boundaries. The Atlas is sold by the Superintendent of Documents (stock no. 003-024-08683-2; $42). Machine-Readable Geographic Files All 1990 census summary tape files include 1990 census geographic area codes, FIPS codes, certain area names, land and inland water area in square kilometers, geographic coordinates for an internal point for each entity, and other geographic information. The Census Bureau developed an automated geographic data base, known as the TIGER (Topologically Integrated Geographic Encoding and Referencing) System, to produce the geographic products for the 1990 census. TIGER provides coordinate-based digital map information for the entire United States, Puerto Rico, the U.S. Virgin Islands, and the Pacific territories over which the United States has jurisdiction. The TIGER System has significantly improved the utility of 1990 census maps and geographic reference products. Extract files generated from the TIGER System permit users, with appropriate software, to perform such tasks as linking the statistical data in the P.L. 94-171 file or the STF's and displaying selected characteristics on maps or a video display screen at different scales and with whatever boundaries they select for any geo- graphic area of the country. For example, a map for a particular county could show the distribution of the voting age population by city block. The first extract of selected geographic and cartographic information intended for computer applications, such as plotting maps and building geographic information systems, is called the TIGER/Line(TM) files. TIGER/Line(TM) files (released on tape and CD-ROM) contain attributes for the segments of each boundary and feature (for example, roads, railroads, and rivers), including 1990 census geographic codes for adjacent areas, latitude/longitude coordinates of segment end points and the curvature of segments, the name and type of the feature, and the relevant census feature class code identifying the feature segment by category. TIGER/Line(TM) files also furnish address ranges and associated ZIP Codes for each side of street segments that have city-style (house number/street name) addresses; provide the names of landmarks, such as lakes and golf courses; and include other information. The 1992 version also includes school district codes, 1990 census urbanized area codes, codes for districts of the 103rd Congress, and address range coverage expanded to include all areas that have city-style addresses. TIGER/GICS(TM) file is another extract. This file contains a total of 12 files, organized on a national or State-by-State basis, for a variety of geographic entities, such as metropolitan areas and their components as of the 1990 census, 1990 census urbanized areas and their components, American Indian and Alaska Native areas and their related states and counties, as well as more familiar entities including counties with their county subdivisions and places). This file contains high-level geographic names, codes, and relationship information. It can be used to link geo- graphic entity names to the codes in the TIGER/Line(TM), TIGER/SDTS(TM) and other TIGER extract files. It also contains 1990 census population and housing counts, population density (CD-ROM version only, but can be calculated using the tape version), and area measurement information (including land area, total water area and separate measurements for each of the four components of water--Inland, Great Lakes, Coastal, and Territorial), as well as the latitude and longitude for an internal point within each geography entity. The TIGER/GICS(TM) also includes corrections to names for selected entities and corrections to the FIPS 55 codes for county subdivisions and places. The first 300 characters of each record in this file are the same as those in the Data Dictionary for the Summary Tape Files; and additional 100 characters provide the above mentioned corrections and components of water. Listings of the files in the TIGER/GICS(TM) may be offered. Call Customer Services at 301-457-4100. Other TIGER System extracts, such as TIGER/Census Tract Comparability(TM) file and TIGER/UA Limit file, are released on computer tape and, in some cases, CD-ROM. For information on TIGER extract files, contact Customer Services.
The Census Bureau issues several reference publications for data users.
Some are sold by the Superintendent of Documents; others are distributed
free by Customer Services. Addresses and phone numbers for the Superin-
tendent of Documents and Customer Services are given in the following
section.
1990 Census of Population and Housing, Guide. This guide, in the
1990 CPH-R report series, provides detailed information about all
aspects of the census and a comprehensive glossary of census terms.
Sold by the Superintendent of Documents, U.S. Government Printing
Office. (Part A, Text: stock no. 003-024-08574-7, $11. Part B,
Glossary: stock no. 003-024-08679-4, $5.50.)
1990 Census of Population and Housing Tabulation and Publication
Program. A free report describing 1990 census products, comparing
1990 products with those of 1980, and more. Request from Customer
Services.
Census '90 Basics. A free booklet covering how the 1990 census data
were collected and processed, the full range of data products, the
maps and geographic files, and more, but with less detail than the
Guide (above). Request from Customer Services.
Census ABC's--Applications in Business and Community. A free booklet
that highlights key information about the 1990 census and illustrates
a variety of ways the data can be used. Request from Customer
Services.
Maps and More. A free, tabloid-size booklet that describes the
geographic entities for which the Census Bureau tabulates data.
The booklet provides information on the types of geographic
entities, how their boundaries are established, and how they
relate to each other. It also covers how these entities differ
among the censuses and surveys and describes the geographic products
available from the Census Bureau. Request from Customer Services.
Strength in Numbers. A free, tabloid-size booklet designed to
assist people in using 1990 census data in redistricting. Among
other features, it includes illustrations of maps and Public
Law 94-171 counts. Request from Customer Services.
TIGER: The Coast-to-Coast Digital Map Data Base. A free booklet
describing the structure and uses of the Census Bureau's TIGER
System. Request from Customer Services.
Census and You. The Census Bureau's monthly newsletter for data
users. It reports on the latest 1990 census developments, selected
new publications and computer tape files, other censuses and surveys,
developments in services to users, and upcoming conferences and
training courses. Subscriptions are sold by the Superintendent of
Documents, U.S. Government Printing Office.
Monthly Product Announcement. A free monthly listing of all new
Census Bureau publications; microfiche; maps; data files on
tape, diskettes, or CD-ROM; and technical documentation. To
subscribe, contact Customer Services.
Census Catalog and Guide. A comprehensive annual description of
data products, statistical programs, and services of the Census
Bureau. It provides abstracts of the publications, data files,
microfiche, maps, and items online. In addition, the Catalog/Guide
offers such features as information about censuses and surveys and
telephone contact lists of data specialists at the Census Bureau, the
State Data Centers, and other data processing service centers. It is
sold by the Superintendent of Documents, U.S. Government Printing
Office.
Users also can get listings of new Census Bureau products, updated
daily, by subscribing to the Daily List. This information and selected
statistics are available online through CENDATA (TM), the Census Bureau's
online information service. For more information, contact Customer
Services.
U.S. Bureau of the Census The Census Bureau's Customer Services sells most of the machine- readable data products, microfiche, and maps described earlier. (The 1990 census printed reports are sold by the Superintendent of Documents, as noted below.) Also, users may consult with specialists at the Census Bureau's Washington headquarters and its 12 regional offices. From time to time, the specialists also conduct workshops, seminars, and training courses. Washington, DC, Contacts--To order products, for a telephone contacts list of Census Bureau specialists, and for general information: Customer Services, U.S. Bureau of the Census, Washington, DC 20233, telephone 301-457-4100 (FAX number, 301-457-4714). For special tabulation information: Population--Rosemarie Cowan, Population Division, U.S. Bureau of the Census, Washington, DC 20233, telephone 301-457-2408; Housing--Housing and Household Economic Statistics, U.S. Bureau of the Census, Washington, DC 20233, telephone 301-763-8553. Microdata--Carmen Campbell, Data User Services Division, U.S. Bureau of the Census, Washington, DC 20233, telephone 301-457-1139. Regional Office Contacts-- Atlanta, GA 404-730-3833 Boston, MA 617-424-0510 Charlotte, NC 704-344-6144 Chicago, IL 708-562-1740 Dallas, TX 214-767-7105 Denver, CO 303-969-7750 Detroit, MI 313-259-1875 Kansas City, KS 913-551-6711 Los Angeles, CA 818-904-6339 New York, NY 212-264-4730 Philadelphia, PA 215-597-8313 Seattle, WA 206-728-5314 Superintendent of Documents, U.S. Government Printing Office The Superintendent of Documents handles the sale of most of the Federal Government's publications, including 1990 census reports. To order reports and for information: Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402, telephone 202-512-1800. Other Sources of Products and Services State Data Centers--The Census Bureau furnishes data products, training in data access and use, technical assistance, and consultation to all States, the District of Columbia, Guam, Puerto Rico, and the U.S. Virgin Islands. State Data Centers, in turn, offer publications for reference, printouts from computer tape, specially prepared reports, maps, and other products and assistance to data users. For a list of the State Data Centers, see the Census Catalog and Guide or contact Customer Services. The list also notes organizations in States participating in the Census Bureau's Business/Industry Data Center (BIDC) Program. The BIDC's help business people, economic development planners, and other data users obtain and use data. Census Information Center (CIC)--The CIC program provides data-related services for nationally based nonprofit organizations that represent minorities or other segments of the population who have been historically undercounted in decennial censuses. The participants include social service, business, professional, civil rights, educational, and religious groups. Through the project, five nonprofit groups now offer their clientele reports, computer tape printouts, and other information from the Census Bureau. To learn more about the program, write to the Data User Services Division, Bureau of the Census, Washington, DC 20233, or call 301-457-1305. National Clearinghouse--The National Clearinghouse for Census Data Services is a listing of private companies and other organizations that offer assistance in obtaining and using data released by the Census Bureau. For a list of participants in the National Clearinghouse, see the Census Catalog and Guide or contact Customer Services. Depository Libraries--There are 1,400 libraries that receive (from the Government Printing Office) Federal publications that they think their patrons will need. Often some of these publications are Census Bureau reports. The Census Bureau provides free reports to an additional 120 census depository libraries. Also, many libraries purchase census reports and maps for their areas. The Census Catalog and Guide includes a list of all depository libraries.