HOW TO USE THIS FILE
CONTENTS
Introduction
Using the File
INTRODUCTION
This chapter serves as a guide for data users to both the tape and the
technical documentation. Novice users trying to understand how to use the
documentation and the file should read this chapter first.
The SSTF 12 file has A and B records. The A records present data for all
persons in 17 population (PA) tables and in 3 housing (HA) tables. The B
records present more detail in 9 population (PB) tables. The Table (Matrix)
Outlines chapter gives a complete description of all tables in the A and B
records.
Documentation Chapters
The Abstract chapter in this documentation provides a quick overview of the
file, including the formal title, geographic coverage, subject coverage, and
file availability. Also shown are citations for related reference materials
and printed reports. Their titles and geography are included in this
section, along with purchasing information.
The Subject Locator is an aid to finding which tables provide the
information needed. The List of Tables (Matrices) and the Table (Matrix)
Outlines provide two types of presentations for the tables available in the
file. The List of Tables (Matrices) has the table titles and universes.
The Table (Matrix) Outlines offer a detailed presentation of the tables.
When reviewing the tables, remember that a colon(:) following an entry
indicates the entry is a heading, not a data cell.
User Notes
Information about file or documentation changes sometimes becomes available
after the documentation has been printed. User notes inform the user
community about these changes. These are issued in a numbered series. If
there are technical documentation changes, revised pages usually accompany
them. The revised pages should be inserted in their proper location, but the
user note cover sheet should be filed in the User Notes chapter. Technical
notes, which contain file errata, are also issued by the Census Bureau. We
suggest filing these following appendix H.
Data Dictionary
The data dictionary describes the file and provides character locations for
each variable and each table. It has two elements, the identification
section and the table (matrix) section.
In the identification section, the components include the field name; the
data dictionary reference name, a short mnemonic for use with software
packages; field size; starting position; and data type (alphabetic, numeric,
or alphanumeric).
The identification section of the data dictionary is identical for all
summary tape files. It provides a list of the geographic codes or refers the
user to the appropriate source. Review the footnotes carefully; they provide
explanations for various terms. These footnotes are listed at the end of the
identification section of the data dictionary.
The table (matrix) section provides information on the table (matrix)
number; table (matrix) description; number of implied decimals in each cell
(if not 0); starting position within the record, within the segment, and for
all cells within the first-level variable; and cell coordinates.
There also is a machine-readable data dictionary file on the data tape.
This dictionary is designed to be converted for use with various software
packages.
Appendixes
Detailed information on geographic areas is in appendix A followed by
subject-matter definitions in appendix B. Appendix C provides detailed
statistical information about the data while appendix D outlines the data
collection and procedures. Facsimiles of both the respondent instructions
and 1990 census long-form questionnaire are in appendix E.
Appendix F furnishes detailed information on all the data products of the
1990 census, as well as suggested sources of information and assistance. The
record layout for the machine-readable data dictionary file that accompanies
each tape order is in appendix G.
Appendix H contains the code lists used in processing the data. These
codes are used in conjunction with the table (matrix) outlines and data
dictionary chapters.
Count Corrections
The Census Bureau issues population count corrections on an occasional
basis. Count corrections for geography at the place level and above are
available from Customer Services, Data User Services Division, Bureau of the
Census, Washington, DC 20233. Count corrections for geography at the census
tract/BNA level or below are available from Population Division, Bureau of
the Census, Washington, DC 20233. When requesting these corrections, please
include the desired census tract/BNA, block group, or block numbers.
USING THE FILE
Internal File Labels
System Labels--Tape orders which specify labeled tapes will have a standard
American National Standards Institute (ANSI) label. The system label
consists of 17 characters, 12 characters are used and the last 5 are "x"
filed. The 1990 SSTF 12 file has a Data Set Name (DSN) of SSF12XUS.Fnnxxxxx,
where nn is a two-digit number with leading zeros identifying the tape volume
sequence. (The "X", "F", and "x" in the DSN remain constant.)
User Labels--Each user tape will have six user header labels and six user
trailer labels. These labels combine information from the system label and
the identification portion of the first and last record. These labels enable
the user to quickly identify the beginning and ending records on each tape.
User Header Labels--The user header labels are designated UHL1 through
UHL6. UHL1 and UHL2 repeat information from the system label in HDR1 and
HDR2. (See the File Information section.) UHL3 and UHL4 contain information
from the identification portion of the first record on the tape. UHL5 and
UHL6 contain a statement regarding the data limitations.
User Trailer Labels--The user trailer labels are designated UTL1 through
UTL6. UTL1 and UTL2 contain
information from the system trailer label. UTL3 and subsequent user trailer
labels contain identification information from the last record on the tape.
The unused portion of UTL6 is blank filled.
File Information
File information, such as record counts, is not provided in the technical
documentation. However, each tape order is accompanied by a tape creation
sheet. This sheet provides the file name, file label (HDR1), the third user
header label (UHL3), record size, block size, and record count. The third
user header label for each reel identifies the geography for the first record
on the reel. For example, the UHL3 at the beginning of each reel of a three-
reel file for a State provides the geography for the first record. If the
geography needed is on reel three, only reel three needs to be processed.
The tape creation sheet received with the tape should be filed in the
technical documentation notebook or with other tape information maintained by
the user.
Summary Level Sequence Chart and Geographic Area Component Codes
The Summary Level Sequence Chart chapter and the geographic area component
codes provide important information for using the 1990 census summary tape
files. The Summary Level Sequence Chart chapter for the SSTF 12 file
identifies the geographic levels for which data are provided.
After identifying the summary level code, turn to chart 3 at the end of
this chapter to determine the geographic area codes and area characteristics
provided on the tape for this summary level. Remember that an asterisk (*)
indicates a code in that field. The code may be one of the standard codes
described below.
The Summary Level Sequence Chart chapter also provides geographic component
code information. This code identifies the various geographic components for
which the record is repeated within the summary level. These component codes
are provided in the identification section of the data dictionary beginning
in position 14. For example, the Summary Level Sequence Chart for SSTF 12
indicates that the summary level for State records (040) has geographic
component code 00. By turning to the geographic component variable in the
data dictionary, you can determine that the tables for summary level 040
(State) are available only for total geography (State) (geographic
component=00).
In short, always check the geographic code, the summary level (beginning in
position 11 of the data dictionary), the geographic component code (beginning
in position 14 of the data dictionary), and the characteristic iteration
(beginning in position 16 of the data dictionary) for complete
identification of an SSTF 12 record.
A and B Records
SSTF 12 is a single file with the data represented in A and B records. The
A and B records can be identified by the characteristic iteration field
(CHARITER, position 16 in the data dictionary).
Each record type presents a different set of tables. The Table (Matrix)
Outlines chapter gives a complete description of all tables in the A and B
records.
The A records have 17 population (PA) and 3 housing (HA) tables. The A
record provides data for all persons for each summary level and geographic
component level within a unit of geography. Since the characteristic
iteration in the A records is always all persons, the A records can be
identified by blanks in the characteristic iteration field.
The B records present more detail in 9 population (PB) tables. The B
records are identified by numbers in the characteristic iteration field.
Chart 1 lists the iteration codes for the A and B records.
Chart 1. Characteristic Iterations
-----------------------------------------------------------------------------
Subject Summary Tape File 12
A Record
Blanks All persons
B Record
NOTE: The codes below are used only in the B records. A blank in this
field indicates an A record.
000 All persons
001 White
120 Not of Hispanic origin
127 Hispanic origin
002 Black
003 American Indian, Eskimo, or Aleut
007 Asian or Pacific Islander
023 Other race
-----------------------------------------------------------------------------
Record Identification
Each record on a summary tape file is uniquely identified by a combination
of specific geographic codes (for example, State code), summary level,
geographic component code, and characteristic iteration. Chart 1 indicates
that for A records and the "000" B record, data are presented for all
persons, regardless of race. The other B records are available for persons
in one of the 25 Asian and Pacific Islander characteristic iterations shown
above.
For example, if you have an SSTF 12 file and want to show the population
for California, table PA1 in the A records file provides data for all
persons. The record providing these data is retrieved by specifying the sum-
mary level code for State records (040), the total record for geographic
components (00), the characteristic iteration for the A record (blanks), and
the State abbreviation for California (CA).
A second example illustrates how to get more detailed information about
Asian or Pacific Islander persons in California. The B records provide tables
for specific characteristic iterations. Therefore, if you want more detailed
data for Asian or Pacific Islander persons in California, you would specify
the summary level code for State records (040), the total record for
geographic components (00), the relevant characteristic iteration for the B
record (007 for Asian or Pacific Islander), and the abbreviation for
California State (CA).
Remember, in both of these examples, you must check all four fields--the
summary level code, the geographic component, the characteristic iteration,
and the State abbreviation--or you will find multiple records.
Record Segmentation
Logical records are divided into segments, each containing identification
information and specific tables. The logical record has a record sequence
number which is repeated in each segment. This is the logical record number
(LOGRECNU) which appears in position 19 of each segment. Following this, in
position 25, is the logical record part number (LOGRECPN). The LOGRECPN
indicates the segment number for a block of data within a record. See Chart
2, Segmentation of the SSTF 12 Records, for a list of segments for the SSTF
12 file. The total number of parts, or segments, in a record (PARTREC) are
shown in position 29.
The A records have 104,884 characters in 13 segments. The B records have
88,748 characters divided into 11 segments. Each segment has 8,068
characters and all of the segments include 300 characters of geographic
identification information followed by tables (matrices). Tables split
across segments are indicated in Chart 2 below. The geographic
identification information layout for each segment is identical to the
identification section described in positions 1-300 of the data dictionary.
Filler characters appear in the record to complete a record segment.
The machine-readable data dictionary, which accompanies the SSTF 12 file,
provides information on these table (matrix) splits across segments.
Chart 2. Segmentation of SSTF 12 Records
-----------------------------------------------------------------------------
Record A
Segment 1
Geographic Identification | PA1--through
Information | PA5--131 data cells
|
| 8,068 characters including
| 1 character filler
Segment 2
Geographic Identification | PA5--863 data cells
Information |
| 8,068 characters including
| 1 character filler
Segment 3
Geographic Identification | PA5--707 data cells--through
Information | PA6--156 data cells
|
| 8,068 characters including
| 1 character filler
Segment 4
Geographic Identification | PA6--863 data cells
Information |
| 8,068 characters including
| 1 character filler
Segment 5
Geographic Identification | PA6--520 data cells--through
Information | PA7--343 data cells
|
| 8,068 characters including
| 1 character filler
Segment 6
Geographic Identification | PA7--863 data cells
Information |
| 8,068 characters including
| 1 character filler
Segment 7
Geographic Identification | PA7--863 data cells
Information |
| 8,068 characters including
| 1 character filler
Segment 8
Geographic Identification | PA7--863 data cells
Information |
| 8,068 characters including
| 1 character filler
Segment 9
Geographic Identification | PA7--659 data cells--through
Information | PA8--204 data cells
|
| 8,068 characters including
| 1 character filler
Segment 10
Geographic Identification | PA8--24 data cells--through
Information | PA11--79 data cells
|
| 8,068 characters including
| 1 character filler
Segment 11
Geographic Identification | PA11--377 data cells--through
Information | PA15--30 data cells
|
| 8,068 characters including
| 1 character filler
Segment 12
Geographic Identification | PA15--464 data cells--through
Information | PA17--133 data cells
|
| 8,068 characters including
| 1 character filler
Segment 13
Geographic Identification | PA17--741 data cells--through
Information | HA3
|
| 8,068 characters including
| 1,072 characters filler
Record B
Segment 1
Geographic Identification | PB1--863 data cells
Information |
| 8,068 characters including
| 1 character filler
Segment 2
Geographic Identification | PB1--677 data cells--through
Information | PB2--186 data cells
|
| 8,068 characters including
| 1 character filler
Segment 3
Geographic Identification | PB2--863 data cells
Information |
| 8,068 characters including
| 1 character filler
Segment 4
Geographic Identification | PB2--337 data cells--through
Information | PB3--526 data cells
|
| 8,068 characters including
| 1 character filler
Segment 5
Geographic Identification | PB3--196 data cells--through
Information | PB4--667 data cells
|
| 8,068 characters including
| 1 character filler
Segment 6
Geographic Identification | PB4--863 data cells
Information |
| 8,068 characters including
| 1 character filler
Segment 7
Geographic Identification | PB4--863 data cells
Information |
| 8,068 characters including
| 1 character filler
Segment 8
Geographic Identification | PB4--863 data cells
Information |
| 8,068 characters including
| 1 character filler
Segment 9
Geographic Identification | PB4--696 data cells--through
Information | PB5--167 data cells
|
| 8,068 characters including
| 1 character filler
Segment 10
Geographic Identification | PB5--99 data cells--through
Information | PB8--192 data cells
|
| 8,068 characters including
| 1 character filler
Segment 11
Geographic Identification | PB8--432 data cells--through
Information | PB9
|
| 8,068 characters including
| 136 characters filler
----------------------------------------------------------------------------
Special Area Codes
Special area codes appear in the geographic area codes portion of the data
dictionary (positions 142-171) on all SSTF's. The codes represented may vary
across SSTF's. Special area code (9) is used in all summary levels on the
SSTF 12 file. The nine codes for special area code (9) are described below.
Special area code (9) Land/water area
1 Significant land, significant (0.0005 or more square
kilometers) water
2 Significant land, minimal (less than 0.0005 square
kilometer) water
3 Significant land, zero (0) water
4 Minimal land, significant water
5 Minimal land, minimal water
6 Minimal land, zero water
7 Zero land, significant water
8 Zero land, minimal water
9 Zero land, zero water
Standard Codes
In the identification section of all summary tape files, there are standard
codes, undefined in the data dictionary, that have identical meaning
regardless of the field. The codes are the same size as the field; that is,
a three-character field will have three symbols. These standard codes are
listed below.
! Not available--The codes would be shown except it had not been deter-
mined when the files were prepared (for example, metropolitan area
code on a county summary level (050) on STF 1A).
9 Not in--This indicates a "remainder of" an area, such as a place
code in the portion of a county subdivision not in a place, or the
summary level is not part of any area to which the code field applies,
such as a summary level which is not in an Alaska Native Regional
Corporation.
Blank Not applicable--This indicates that the code is not applicable to
the summary level.
Where these codes are specifically defined in the data dictionary, the
defined code should be used. For example, in the division code description
on the data dictionary (position 89), the code for the Pacific Division is
indicated as "9." This "9" should be interpreted as the division code,
not as "not in," the standard code for "9."
Chart 3. SSTF 12 File Identification by Summary Level(1)
-----------------------------------------------------------------------------
Summary Level Summary Level
Field Name 010 040 303 304
RECORD CODES
File Identification * * * *
State/US-Abbreviation * * * *
Summary Level * * * *
Geographic Component * * * *
--------------------------------------------------------------------------
Characteristic Iteration * * * *
Logical Record Number * * * *
Logical Record Part Number * * * *
Total Number of Parts In Record * * * *
--------------------------------------------------------------------------
GEOGRAPHIC AREA CODES
Alaska Native Regional Corporation
American Indian And Alaska Native Area (Census)
American Indian And Alaska Native Area (FIPS)
American Indian And Alaska Native Area Class Code
--------------------------------------------------------------------------
American Indian Reservation Trust Land Indicator
Block
Block Group
Census Tract/Block Numbering Area
--------------------------------------------------------------------------
Congressional District
Consolidated City (Census)
Consolidated City (FIPS)
Consolidated City Class Code
--------------------------------------------------------------------------
Consolidated City Size Code
Consolidated Metropolitan Statistical Area * *
County
County Size Code
--------------------------------------------------------------------------
County Subdivision (Census)
County Subdivision (FIPS)
County Subdivision Class Code
County Subdivision Size Code
--------------------------------------------------------------------------
Division *
Extended City Indicator
Internal Use Code
Metropolitan Statistical Area/Consolidated
Metropolitan Area * *
--------------------------------------------------------------------------
MSA/CMSA Size Code * *
Place (Census)
Place (FIPS)
Place Class Code
--------------------------------------------------------------------------
Place Description Code
Place Size Code
Primary Metropolitan Statistical Area *
Region *
--------------------------------------------------------------------------
State (Census) *
State (FIPS) *
Urban/Rural
Urbanized Area
Urbanized Area Size Code
--------------------------------------------------------------------------
Special Area Code (1)
Special Area Code (2)
Special Area Code (3)
Special Area Code (4)
Special Area Code (5)
--------------------------------------------------------------------------
Special Area Code (6)
Special Area Code (7)
Special Area Code (8)
Special Area Code (9) * * * *
Special Area Code (10)
--------------------------------------------------------------------------
AREA CHARACTERISTICS
Area (Land) * * * *
Area (Water) * * * *
Area Name/PSAD Term/Part Indicator * * * *
Functional Status Code * * * *
--------------------------------------------------------------------------
Geographic Change User Note Indicator * * * *
Housing Unit Count (100 percent) * * * *
Internal Point (Latitude) * * * *
Internal Point (Longitude) * * * *
--------------------------------------------------------------------------
Part Flag
Political/Statistical Area Description Code * * *
Population Count (100 percent) * * * *
Special Flag * * * *
--------------------------------------------------------------------------
--------
(1)See the Summary Level Sequence Chart chapter for identification
of the summary level record numbers.