NLS Investigator Manual
Table of Contents
CHRR
Database Investigator
CD-ROM
User’s Manual
for NLS Data
May 2002
File size: 540.25 M
Total files: 194
Table of Contents
Chapter 1
Introduction
About This User's Manual
What You Need To Know
What You Need To Have
Conventions Used In This Manual
Compact Disc Care
Cd-Rom Updates
Customer Services And Technical Support
Chapter 2
The CHRR Software
Installing The Software And Data
Running The Software
The CHRR Database Investigator Screen
Title, Menu, and Navigation Bars
Manage Cohorts button
Contents button
Variables button
Text/Cdbk button
Navigating The Windows
Chapter 3
Starting Out
Specifying A Data File For Use
Cohort field
Manange Cohorts Window
Contents Window
Selecting an Index
Locating Index Terms
Chapter 4
Performing An Extract
Specifying A Tagset
Specifying The Sample Size
Case Selection
Boolean Qualification
Boolean Edit Box
To edit the Boolean Phrase
Data File Type Specification
Data Extract Formats
File Size Information
Actions
Run Extract
Write Codebook
Exit this Menu
Chapter 5
Write Documentation
Index Options Tab
List Options Tab
Field Widths Tab
Appendix 1
Main Menu Commands
Command
Description
Shortcut
Manage Cohort Commands
Appendix 2
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Table of Contents
Operators-Commands Menu
Boolean Operators
Positioning Variables
Strategic Commands
The Variables Window
Tagging Variables
Multiple Tagging Functions
Saving Variables
Examining Variables
Text/Cdbk Window
File Names
Extract File Types
Documentation Files
Appendix 3
Sample Files Generated
Chld--88-2ndpreg.CDB
Chld--88-2ndpreg.DCT
Chld--88-2ndpreg.DOC
Chld--88-2ndpreg.SAS
Chld--88-2ndpreg.SPS
Copyright: The Ohio State University - CHRR
NLS Investigator Manual
Introduction
1
Chapter 1
Introduction
About this User's Manual
This User's Manual illustrates how to begin using the Windows version of the data base access software CHRR
Database Investigator. This retrieval system accompanies one or more of the National Longitudinal Survey's
(NLS) databases on CD-ROM. With it you can extract data and prepare that data for statistical analysis. You can
create, modify, and save your own personalized, extracted files for further research. This package is easy to use.
If you already have some knowledge of the NLS and a search strategy in mind, you will be able to complete that
search and extract a file within minutes of using the guide. Just follow this guide and substitute your own strategy
for the examples given.
What you need to know
To get the most out of this User's Manual, you should already be familiar with the NLS and know how your
interests can be served by NLS data. You need some idea of the samples covered and the types of information
collected by the survey instrument. If you have questions about the NLS data, please consult the NLS Handbook
(available in printed edition only). Or you may consult the on-line documents available for the cohort selected.
These documents are available on the CD via: Documents in the Contents window on the initial screen display
of CHRR Database Investigator shown in Figure 7 Contents Window Maximized. For the sample cohort they are
the NLSY79 User's Manual and the NLSY79 Codebook Supplement. For more detailed information, see Chapter
3.
In addition to knowledge of the NLS and its data, you need to have some knowledge of the MicrosoftWindows
operating system. This guide explains in detail how to install and use the Windows version of the CHRR data
extraction software.
What you need to have
Before you install or start the CHRR software make sure you have the following minimum hardware:
1. A PC running Windows and a minimum of 64 megabytes of memory.
2. Between 650-750 megabytes of disk space.
Conventions used in this manual
The following conventions are used throughout this guide.
<Enter>
Anything enclosed in angle braces represents a key on the keyboard. Find the
corresponding key and press it.
<Alt> + <F1>
The plus (+) sign between two keys means hold down the first key and press the second key.
Then release both keys.
bold
Anything that you are asked to type exactly as it appears in the manual will appear in bold
type. For example, if you are asked to type NLSDBA, it will appear in bold. The software is
not sensitive to upper or lower case.
italics
Anything that is a placeholder for variable information will be written in italics. For example, if
you are asked to provide the name of a file it will appear as filename, a letter for a disk drive
as d:.
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Introduction
Compact disc care
Compact discs should be handled with care. Do not touch the surface. Hold the disc by the outside edge and
gently place it in the CD reader. It should be stored in its plastic case. If the surface becomes scratched or
damaged, the CD may become unusable. Never wipe the surface with cloth; it may be air-cleaned.
CD-ROM updates
When a new year of data is added to the NLS database, a new compact disc may be purchased along with the
current software. As the software is refined and updated, new software versions will be issued with the next
available data update. Any major errors in the search software will be released on PC diskette as soon as they
are discovered. Whenever you receive any updated version of the data or software, you must re-install the new
versions.
Customer services and technical support
If you have any customer service questions or technical support problems please contact:





The Ohio State University
Center for Human Resource Research
921 Chatham Lane, Suite 200
Columbus, OH 43221-2418
614-442-7366 "User Services"
E-mail: USERSVC@postoffice.chrr.ohio-state.edu
Copyright: The Ohio State University - CHRR
NLS Investigator Manual
Starting Out
Chapter 2
The CHRR Software
Installing the Software and Data
To install the CHRR Database Investigator, insert the CD in your CD-ROM drive. For the following instructions
assume “D:” is the CD-ROM drive on your PC. You must substitute your CD-ROM drive in the place of “D:”
below.
To install the software

Click the "Start" button on your PC, then click "Run...".

In the "Open" box type "D:\Software\SETUP.EXE", then click "OK".
To decompress ‘nlsy79.zip’

Open "D:\nlsy79.zip" with a decompression program (such as WINZIP®) and unzip to an appropriate
directory, e.g. "C:\nlsdata\",
To add NLSY79 to the NLS DB Investigator

Start CHRR DB Investigator (see the section below, if you do not know how to run the software in your
browser).

Click on "Options | Add a Cohort", select the location you unzipped to (e.g. "C:\nlsdata\nlsy79"), and click
on "Open".

Select “cohort.ini” and click on “Open”.
Running the Software
To run the CHRR Database Investigator from
Windows Explorer, open the drive and
directory where you installed the software
(default C:\Program Files\CHRR\) and
double-click on dbgator.exe. Or, click
Start/Programs/CHRR Software/DB'gator.
When you start the CHRR Database
Investigator software, dbgator.exe, a screen
similar to Figure 1 will appear. The first time
it appears it will be blank and you must select
the source (Cohort) of the data set you wish
to use.
To select the data set, use the drop-down
menu
next to the Cohort field.
When the data set has been selected the
Contents window will display the
Documentation and Indexes that are
available with the data set. From the
Figure 1 CHRR Database Investigator Startup Screen
Contents window, you can control what
appears in the other windows by selecting items in the tree.
You may resize the any of the windows to suit your needs. If you loose track of one of the windows (Contents,
Variables, Text/Cdbk), go to the Window menu and choose Default. The screen will refresh its format similar to
that in Figure 1. The contents of the individual windows will not be lost.
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Starting Out
Figure 2 The Navigation Bar
The CHRR Database Investigator Screen
Before specifying the data set, it may be necessary to say a few words about the layout of the CHRR Database
Investigator screen. The screen is a typical Windows environment with the Command Menu bar just below the
Title bar. The register of commands available for each menu components: File, Window, Extract, Data,
Options, Data, Links and Help can be found by clicking on the menu component A complete list of commands
under each of these components can be found in Appendix 1, Main Menu Bar.
Title, Menu, and Navigation Bars
Just below the Menu bar is the 'Navigation' bar.
It contains the Cohort field, a Manage Cohorts button, and three buttons, Contents, Variables, Text/Cdbk
(Codebook). The data set to be used must be specified in the Cohort field and the Manage Cohorts button can
be used to add, delete, and search for cohorts. The Contents, Variables, and Text/Cdbk buttons switch between
the active windows displayed in the lower portions of the screen. These windows are used to manipulate the data
for extraction (Contents), display the results of manipulation and extraction (Variables), and obtain help in the
form of documentation (Text/Cdbk).
In a Windows environment switching active windows can also be accomplished simply by clicking in the window.
However, if the active window 'covers' one of the inactive windows or the inactive window is minimized, the above
buttons can be used to make the window active and bring it to the forefront. If you loose track of one of the
windows (Contents, Variables, Text/Cdbk) and its button does not bring it to the forefront, go to the Window
menu and choose Default. The screen will refresh its format similar to that in Figure 1 but the contents of the
each window will not be lost. You may then resize.
The windows in the CHRR Database Investigator may be resized according to your preference. You must decide
for yourself what Windows layout you prefer. Once your preferences are established they will remain that way
rather then reverting to the default. It may be easiest to begin with the Contents window maximized in order to
select an index for use, locate index terms, and select the terms for the search strategy. Or you may wish to
review the on-line, hypertext documentation first in the Text/Cdbk window.
Manage Cohorts button
The Manage Cohorts button, when pressed, opens the Manage Cohorts window and makes it the active window
on the screen. From the Manage Cohorts window the user can work with the individual cohorts in the PC's
network neighborhood. In the neighborhood, it can find and distinguish among those cohorts whose location is
already registered with the software from those who are not registered. It can even distinguish among different
versions of cohorts in the Creation Date field.
Contents button
The Contents button, when pressed, makes the Contents window the active window on the screen. The Contents
window is the principal window of the data retrieval program. It allows the user to choose what documentation is
displayed in the Text/Cdbk window and which index is used for data retrieval and display in the Variables window.
Variables button
The Variables window displays the variables found when a search is run or it displays the variables in an extract
specification file when that file is opened. "Name, Description, Record Type, Year, Reference Number, and
Question Name" information document the variables displayed.
Text/Cdbk button
The Text/Cdbk window shown in the Figure 2 above provides links to this manual and to other documentation.
Copyright: The Ohio State University - CHRR
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Starting Out
Navigating the Windows
In a Windows environment switching active windows can be accomplished simply by clicking in the window.
However, if the active window 'covers' one of the inactive windows or the inactive window is minimized, the
buttons below can be used to make the inactive window active and bring it to the forefront.
Each window can be minimized by clicking on the X in the size bar:
The double-square button will reduce the size of the window to less than full size.
The large square will make the active window fill up the full screen and hide the other windows.
The X button will minimize a particular window. Caution: However, if the 'X' button in the CHRR CHRR
Database Investigator title bar is clicked, this will shut down the application and any unsaved data will be
lost.
Next Steps
Select a Cohort to investigate and begin developing a search strategy within the Contents window. Or maximize
the Text/Cdbk window and view on-line, hypertext documentation.
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Starting Out
Chapter 3
Starting Out
Specifying a Data File for Use
In order to begin to develop a search
strategy, a data set, or cohort, must be
Figure 4 Manage Cohorts
specified in the Cohort field. Depending on
which of the three options were selected in "Setting Up the CHRR Software," you may have to insert the CD into
you CD-ROM drive. Figure 3 shows the default display for the Contents, Variables, and Text/Cdbk windows. You
may resize the windows according to your preferences or click on the Window option in the menu bar and choose
a pre-specified command from its drop-down
menu .
Cohort Field
To specify a cohort, use the drop-down
menu in the Cohort field to see the data
sets available. Click on the data set you
want to investigate.
Once a data set is specified a list of the
indexes and documents that are associated
with the data set will appear in the Contents
window. The two other windows, Variables
and Text/Cdbk, are used to receive data
depending on choices made in the Contents
window. The windows will be discussed in
the following order Contents, Variables, and
Text/Cdbk.
Figure 3 also shows the Text/Cdbk window
displaying the CHRR Investigator User's
Manual documentation.
Figure 3 Database Investigator Main Window's Components
Manage Cohorts
When you click on the Manage Cohorts button, the window in Figure 4 opens. If you have never used the
software or you have no cohorts registered with the software, when the window opens it will be blank. You must
begin by using the File menu and search your PC to find the cohorts (datasets) that you have downloaded and
(unzipped) decompressed on your hard drives, and/or that are on the CD-ROM disc, and/or on your network
drives. To begin, move the cursor to Search for Cohorts.
When you select Search for Cohorts from the File menu, you will then be asked to specify what drive(s) you want
to search for existing datasets (cohorts): Hard Drives, CD-ROMS, Network Drives. You may select one or all of
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Starting Out
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the choices. Then the software will search the drive(s) you specified and display the results, if any, in the window
similar to Figure 5 below.
Search Results
The results of the Search for Cohorts feature identify the location (path, directory, name) and creation-date for
each cohort that resides within the network neighborhood (disk drives, cd-rom drives, and network drives that you
included in your search) of your PC. If there are cohorts whose locations are already recognized and registered
by the software, those cohorts will appear in the window with a checkmark (see Figure 5). The cohorts in the
network neighborhood that are recognized but whose locations are not registered by the software (and presently
unavailable to it) will also appear in the window but without a checkmark.
To register a cohort, check its box. To un-register a cohort, uncheck it box.
The Creation Date of the cohort may be used to distinguish among multiple releases or versions of similar
datasets.
Figure 5 Search for Cohorts Results
Commands in the File Menu
To Add
(or register) a cohort to the software, it must be checked. If it is already checked, it is
already registered in the software.
To Remove
(or un-register) a cohort, the simpler way is to uncheck it in the window. Then, when
the window is closed, it will no longer be available to the Database Investigator software
for manipulation and it will no longer appear in the Cohort field as one of the available
datasets. If you really want to delete a cohort and its associated files, this is the
command!
NOTE: If you choose to use this Remove command, you will be asked in an
intermediary step if you would like 'to delete the files associated with' the highlighted
cohort.
 If you do not delete the files, they will remain on the disk and will be found again the
next time you use the Search for Cohorts command. Choosing to not delete the files
is the equivalent of unchecking the cohort.
 If you wish to delete the files and choose 'yes', they will be removed from your hard
disk and you would have to re-install them again as if you were installing a new
dataset.
To Explore
an individual cohort listed in the window, its Description, Cohort Name, Directory and
Creation Date must first be highlighted by clicking on the cohort, then the Explore
command in the menu should be selected. The Explore command opens a standard
Windows Explorer dialogue box at the path and location of the dataset.
Contents Window
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Starting Out
The Contents window shown in Figure 6 and
maximized in Figure 7 is the principal window
for data retrieval and is used to navigate
among documentation, indexes, and variable
displays for a specified cohort. It controls the
selection of the components that are
available for the selected cohort. Depending
on the cohort selected, different
documentation and indexes may be
available. The contents window is also used
to develop a search strategy of selected
variables. To work with the Contents
window, it may be best to maximize it as
shown in Figure 7.
When the Contents window is maximized its
three frames from top to bottom can be
viewed better. The frames from top to bottom
are:
1. The top frame or Components of the data Figure 6 Database Investigator Main Window's Components
set that include available documentation
and indexes to the variables that are available in the data set. To select a specific index, click on + Indexes
expand the tree and display the contents of the available indexes; then double-click on the desired index
name;
2. The middle frame or Index Terms available in the selected Index, and a 'Search for' engine to speed up
variable selection; and
3. The bottom frame or Items (i.e., variables) selected from various indexes that are being assembled into a
Boolean search strategy.
Selecting an Index
The Components of the data set (top frame)
allow the user to switch access to the
principal indexes of the data set and to select
the documents to appear in the Text/Cdbk
window. The available indexes may vary
from one data set to another. For example,
the 'Area of Interest' index has replaced the
previously used Record Type index. To view
the contents of an index, double-click on the
index name and its contents will appear in the
Index Terms frame (middle).
The available indexes in the currently
selected data set are named:
Any Word in Context is an index to all words
used in the variable title. The number of
occurrences (Entries) appears with the word.
Area of Interest (formerly Record Type) is an
index to categories of variables that are
grouped by areas of interest and assigned to
Figure 7 Contents Window Maximized
the variable.
SurveyYear is an index to variables used in a Survey year.
Refnum is an index to variables by reference numbers, i.e., a number that is assigned to variables in order to
locate them across survey years.
Qname is an index to variables by question name and locates them across years.
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Locating Index Terms
To locate a desired term in an index, scroll down to it in the middle frame by using the scroll bar. Or search for a
term, by using the Search for field. Begin typing in the name of the term in the Search for field and the list will
scroll down to the first occurrence of that combination of letters. To include an index term in a Boolean search,
left-click on a term to highlight it and drag it down to the Item frame (bottom) to select it. Variables must be
placed in the Item frame to run a Boolean search on the variables. If the Boolean search is successful, the
variables associated with the selected terms will be extracted for further examination and manipulation. The
variables extracted, as the result of a search, will appear in the Variables window.
To view all occurrences of a variable (Index term), double-click on its name. Each occurrence (equal to the
number of Entries) of the variable along with brief documentation will appear in the Variables window.
above shows three variables each selected from a different index. CHILD was selected from the Any Word in
Context index, 1998 from the Year index, and 2ND PREGNANCY from the Keyword in Context index.
Operators-Commands Menu
A variable that appears in the lower Item frame may be manipulated via the OperatorsCommands pop-up menu. To view the Operators-Commands pop-up menu, right-click on
the desired item name (variable) to highlight it and bring up the pop-up menu. The pop-up
menu is comprised of the following three parts:



Boolean operators at the top;
Variable position commands, in the middle; and
Strategic commands at the bottom.
Figure 8 Operations
Boolean Operators
To change one of the operators in the Operator column of the Search Strategy frame, right-click on it and the
operators-commands menu will appear. To select a different operation (AND, OR, NOT), move the highlight bar
to it and click. It will change in the Operator column.
Positioning Variables
To change the position of a variable in the Item column, right-click on it and the operators-commands menu will
appear. To move the variable in the list, move the highlight bar to the choice (Move up or Move down) and click.
The variable will move accordingly in the Item column.
Strategic Commands
To clear all variables in the Item column, right-click anywhere in the lower frame and the operators-commands
pop-up menu will appear. Move the highlight bar to Clear and click and all the variables in the lower frame will
disappear.
To delete a variable in the Items list, right-click on the variable to highlight it and bring up the operatorscommands dialogue box. Move the highlight bar to Delete and click.
To run or apply the Boolean search strategy, right-click anywhere in the lower frame and the operatorscommands pop-up menu will appear. Move the highlight bar to Apply and click. The search will be run and if the
Boolean search is successful, the variables associated with the selected terms will be extracted and displayed in
the Variables window for further examination and manipulation. The Variables window will appear displaying the
variables.
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Starting Out
The Variables Window
The Variables window displays the variables
resulting from a successful search or those
saved in previously tagged set when it is
opened. Variables appearing in the window
may be saved, tagged for saving or
untagged, or examined in further detail.
Tagging Variables
When a variable is tagged a checkmark is
placed in the checkbox in the left most
column. When a variable is untagged, no
checkmark appears.
To place a checkmark in the checkbox, click
in the box next to the desired variable. To
remove a checkmark, click in the box where
the checkmark appears and it will disappear.
To tag all variables at the same time, rightclick anywhere in the variables’ window and
the Tagging Pop-up Menu shown in Figure
10 will appear. Highlight the Tag All option
or press <F5>.
Figure 9 Variables from Search Run
Multiple Tagging Functions
In the Variables window, multiple variables may be selected for tagging or untagging. All variables may also be
tagged or untagged at once. Figure 10 shows the four functions available to make multiple selections.
To tag or untag all variables in the list, right-click anywhere within the variables list window. Move the pointer to
the Tag All or Untag All and click. Checkmarks will appear or disappear, appropriately. An alternate method is
to simply press <F5> or <F6> when the Variables List is the active window.
To tag multiple but not all variables, the variables must be selected. Selected variables are those that are
highlighted.


To highlight a contiguous block of variables, click on the first one in the block then
hold down the <Shift> key and click on the last one in the block. <Shift> + Click.
When the block is highlighted, place the pointer over one of the highlighted variables
and right-click. The Tagging Pop-up Menu will appear. Move the pointer to the Tag
Selected and click. A checkmark will appear next to those selected. An alternate
method is that when all the desired variables are highlighted, <F3> may be pressed
to place the checkmarks.
Figure 10 Pop-up
Menu
To highlight non-contiguous variables, hold down the <Alt> key and click on each variable to highlight. <Alt>
+ Click. When the non-contiguous variables are highlighted, place the pointer over one of the highlighted
variables and right-click. The Tagging Pop-up Menu will appear. Move the pointer to the Tag Selected and
click. A checkmark will appear next to those selected. An alternate method is that when all the desired
variables are highlighted, <F3> may be pressed to place the checkmarks.
Saving Variables
To save tagged variables, click on File in the menu bar, move the highlight bar to Save Tagset… and click. The
standard Windows dialogue box will appear asking you to name the file and specify the location of the file to save.
An extension, in this instance for the NLSY79 public releases, ".ythpub" will be attached to the extract
specification files (tagsets) used to store variables Each cohort will have a unique identifier. All other extensions
stay as they were. To see a list of file name extensions, see Appendices, File Names.
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Examining Variables
To view a single variable in detail, double-click on it in the Variables window and it will appear in the Text/Cdbk
window. Or, highlight the variable in the Variables window by right-clicking on it. The Tagging Pop-up menu will
appear as shown in Figure 10 above. Move the highlight bar to Codebook and click to see the codebook
description of the variable. An alternate method to bring up the codebook display is to press <F2> when a variable
is highlighted.
Text/Cdbk Window
The Text Codebook window is a browser, but you cannot change the URL that appears in the URL field. The
browser is limited to browsing the documentary material associated with the cohort specified in the Cohort field.
The buttons that appear next to the URL field in the the Text Codebook window perform standard browser
functions. All hyperlinks that appear in the Text Codebook window are active and may be followed by clicking on
them.
Browser Buttons
Back
Go back one browser window.
Forward
Go forward one browser window.
Refresh
Renew the contents of the browser window.
Stop
Stop loading the contents into the browser window.
Font Size
Adjust the size of the display font in the Text Codebook window.
The codebook display of a variable appears in the Text/Cdbk window shown in Figure 11. Notice how closely the
codebook documentation resembles the question in the survey. This is because the OSU CHRR CAPI for
Questionnaire Design is a self-documenting system in which each question-response pair becomes a meta-datum
documenting itself.
Information that identifies the variable is
found at the top of the codebook display:
Variable number, Variable label, Question
number, Year used, Record type (or Area of
Interest), and Variable name.
Variables related to the current one are
mentioned as 'see' references in the middle
of the of the display: e.g., SEE R(26048.).
The frequencies of the responses selected,
including Refusals and Don't Knows, and
Valid/Invalid Skips complete the codebook
description of the variable. (See cohort
specific Users' Guide, section "Accessing
Variables By Codebook", for a detailed
explanation of codebook conventions.)
Detailed information from the codebook can
be used to determine if the variable is one to
keep in the extract specification file or if it
should be discarded.
Figure 11 Codebook Display of a Variable
The Back and Forward buttons control what is displayed in the Text/Cdbk window. Like in you Internet browser,
Back will go back to the previous display in the window, if applicable, and Forward will go to the next one, if
applicable.
To go back to the Variables window, press the Variables button on the Navigation bar. To go to the Contents
window, press the Contents button.
Next Steps
After completing a search and creating an extract specification file, the next step is to setup and run the extract.
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NLS Investigator Manual
Performing an Extract
Chapter 4
Performing an Extract
Specifying a Tagset
To perform an extract, an existing tagset
must be open. To open a tagset, go to the
File component of the Menu bar and choose
Open Tagset… Browse and select the
desired tagset from the standard Windows
dialogue box. When the tagset is open, go to
the Extract component of the Menu bar and
Figure 13
12 Selecting
Extract Window
the Number of Cases
choose Extract Saved Variables. Before
choosing to extract saved variables you may wish to review them (and edit them) by choosing Review Saved
Variables.
When the function Extract Saved Variables is activated, the screen shown below in the will appear. From this
window you may finalize the data file to be extracted in several ways:



The sample universe of cases may be qualified by limiting the number of cases in the sample and/or by
pressing the Edit Boolean Specification to create a Boolean phrase (left half of window).
One of the file characteristics for the output file may be specified under the Extract Data File Type portion of
the window by clicking on a file type and additional output files may be specified under the Optional Output
File portion of the window.
Finally two options can be carried out on the file: Run Extract or Write Codebook.
The Menu Bar contains the actions to carry out on the sample universe: Run Extract, Stop Extract, Write
Codebook, and Exit the extract.
The left half of the window is used to qualify the sample universe of cases by limiting the range of cases and by
creating a Boolean Specification.
The right half of the window is used to select the format(s) of the output file.
Information about the extract file such as name, sample size (Number of variables and Number of cases), output
record length, and output file size is found in the lower right half of the window.
To make selections in the extract window, press a button, click in a field and type in the limits, or click on a radio
button and or check box.

A Radio button (

A Check box (
) is a button that when clicked excludes other choices in the list.
) is a button that when clicked selects the option listed. Multiple choices may be checked.
Specifying the Sample Size
The left half of the window allows the user to manipulate the size of the sample universe by combining four
methods. Each method is discussed below.
Case Selection
The number of cases in the sample universe may be changed in several ways. The number of cases selected for
the extract may be altered and a fraction of the cases may be selected for extraction, the first and last cases read
may be changed, and a Boolean specification may be run against the variables in a case to include or exclude
them.
Select Number of Cases
To change the number of cases read,
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

Performing an Extract
13
Place the cursor in the Select 1 of every
__ case(s) field; and
Type the denominator integer in the
blank.
First Case to Read
Instead of always beginning with the first
case in the file another may be specified as
the beginning case.
To change the first case read,


Place the cursor in the "First case to
read" field and
Type in the integer of the first case to
read.
Last Case to Read
15 Create
The Boolean
Phrase
Figure 14
a Boolean
Specification
To change the last case to read,


Place the cursor in the "Last case to read" field; and
Type in the integer of the last case to read.
When any or all of the "selected number of cases", the "first case to read", or the "last case to read" are changed
and the cursor is placed in another field, information in the "Number of cases" field will change correspondingly.
(Compare the number of cases in and to the right.)
Boolean Qualification
When the “Edit Boolean Specification” button is pressed, the window shown in Figure 14 will appear. The
Boolean phrase constructed will further manipulate the sample universe by performing operations on the
extracted variables that are listed in the right box of the window.
The Boolean phrase is constructed in the top box by selecting variables from the list and qualifying them with the
Boolean and arithmetic operators listed, constants, and variables.

Rules of arithmetic syntax such as balanced parentheses must be followed.

The maximum length of the Boolean string allowed is 255 characters.
If violations of syntax or length occur, an error message will be displayed.
Boolean Edit Box
In the phrase is constructed in the top box. You may type the information in the box, you may use the buttons
and variables displayed on this screen to select the variables and operators, or you may use a combination of
both. When a variable is highlighted in the list box on the right, the Description of the variable will appear across
the bottom of the screen (e.g., 2nd PERIOS OF PAID LEAVE…).
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NLS Investigator Manual
Performing an Extract
To place one of the extracted variables (e.g.,
R5266600) in the construction box at the top,
double-click on it in the box on the right.
(You may also select a variable by clicking
on the Variable button. The Variable field
will appear with the Accept and Cancel
buttons. Then select it from the list in the
drop-down menu and press the Accept
button.)
To place one of the operators (e.g., >) in the
construction box, type it, or click once on its
button.
To place a constant (e.g., 0) in the
construction box, type it, or click on the
Constant button. (When you click on the
Constant button, the constant field will
Figure 16 Output File Types
appear with the Accept and Cancel buttons.
Use the  or to increase or decrease the number in the field and press the Accept button when the number is
correct.)
To edit the Boolean Phrase
In the top box, place the cursor at the location in the phrase where the edit will occur and click to activate the text
cursor. You may now begin typing to insert, or press Delete to delete the next character, etc/ In standard
Windows fashion, double-clicking over a variable or operator will select the whole term by highlighting it and you
can delete it or begin typing to replace the selection.
When the phrase is complete, press the Exit button to exit and save the Boolean specification. Or, press the Quit
button to exit and not save the Boolean specification.
Data File Type Specification
Output file specifications may be changed. Each specification available for a selected cohort is listed in the right
half of the window in .
In the Extract Data File Type portion of the window the desired extract file type is selected. Depending on the
size of the Cohort selected and the form of the compression used, some extract file types may not be available
(e.g., SAS and SPSS). The extract file types are mutually exclusive. That means that if the radio button for one
extract data file type is toggled ‘ON’ (
), no others may be selected.
In the Optional Output Files portion of the window one or more file types may be selected by placing a check mark
in the check box ( ). Multiple choices in the list may be checked.
Data Extract Formats
The following file formats are available in the Extract Data File Type portion of the window.

A formatted ASCII file is a raw file in which each datum is located in a fixed position, i.e., column, in each
record.
 A delimited ASCII file is a raw file in which each datum is separated by a comma. This format can be read by
many statistical packages, spreadsheets, and programming languages.
 A DBASE 3 file is a database file that can be read by Dbase software.
 A Stata Dictionary is a file that can be used with Stata software.
Depending on the cohorts available, their size, and due to various forms of compression on the CD the following
options may be displayed:

SAS control cards describes a file that can be generated to read the binary data file directly from the
compact disk. These can be used to run PC-SAS to perform any desired SAS procedure such as creating
Copyright: The Ohio State University - CHRR
NLS Investigator Manual

Performing an Extract
a SAS system file. (This specification
conserves disk space because it
eliminates the need to create a raw file
on the PC hard disk that will ultimately be
used to create a SAS system file.)
SPSS control cards describes a file
that can be generated to read the binary
data file directly from the compact disk.
These can be used to run SPSS to
perform any desired SPSS procedure
such as creating a SPSS system file.
Note: The SAS and SPSS control statements
generated include basic data location, label
and missing value information. While every
attempt has been made to provide “read-touse” statements, the platform and version of
Figure 18 Extract In-progress
your specific installation may require
modification of these generic control
programs. Please consult your local SPSS or
SAS coordinator for site-specific problems.
File Size Information
In the right half of the window, lower portion,
information about the extract file is displayed
in the fields listed below. The original size of
the sample universe and output file size
appears when the window appears. As the
size of the sample universe is changed, this
information is reflected in the fields. Other
fields display the length of the record in the
file and the output file name.





Figure 17 File Size Information
Number of variables
Number of cases
Output record length
Output file size
Output file name
Actions
Several actions may be carried out on the extract file. The buttons in the menu bar controls these actions.




Run Extract begins the extract.
Stop Extract cancels the running extract.
Write Codebook produces the codebook for the extract specification file.
Exit abandons all processing and closes this window.
Run Extract
Carefully read the screen to assure that all selected specifications are correct.
When they are correct, press the Run Extract button. Figure 18 shows the extract operation in-progress.
Information about the progress of the extract will appear at the bottom left of the screen.
The Stop Extract button becomes active and the extract may be aborted when it is pressed.
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Performing an Extract
Summary information on the extract run will
appear at the end of processing. This
information includes the resulting number of
cases read, cases kept, and elapsed time.
The resulting output files are listed by name.
Press the Exit button to close the window
and return to the Extract window.
Figure 19 Extract Report
Write Codebook
Normally the Codebook file of the extract file is produced automatically. But when only the codebook is desired,
this button can be used without running the extract. When the Write Codebook button is pressed, no window
appears on the screen. A codebook file is created and placed in the directory where the software was installed.
This file contains a codebook representation of the variables in the extract file. The name of this codebook file is
the same file name as extract file with a .CDB extension, e.g., [filename].CDB.
NOTE:
This codebook file should not be confused with the complete codebook file created when the Write
Documentation function is selected from the File component of the Main Menu screen. The file name of
the complete codebook will be specified at the time of creation.
Exit this Menu
When the Exit button is pressed, the user is returned to the Main Menu screen.
Next Step
Chapter 5 - Write Documentation or view sample extract files: chld-88-2ndpreg.CDB, chld--88-2ndpreg.DCT,
chld-88-2ndpreg.DOC, chld-88-2ndpreg.SAS, chld-88-2ndpreg.SPS.
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NLS Investigator Manual
Documentation
17
Chapter 5
Write Documentation
When the Write Documentation function is
selected from the File component of the
Menu bar, the Create Documentation Files
window appears and allows the user to
select from a number of documentation
options.
The buttons at the top of the window perform
the actions on the files. To specify an
Output Location, type it in the box or use
the Browse button to browse for the output
locations.
Figure 22
20 List
21
WriteOptions
Index
Documentation
Options
Tab
Tab
Window
The Create Codebook check box will create
the complete codebook for the data set selected in the Cohort box on the Main Menu. Caution: the data sets are
large and a codebook for the complete data will be a large file.
The tabs in the middle of the window control the type of documentation produced and the format.
The Index Options Tab - creates documentation for one or more indexes.
The List Options Tab - creates documentation for the variable names and or the question names.
The Field Widths Tab - allows the user to specify the format of the output.
Index Options Tab
Use the Index Options tab to select the index for which documentation will be produced. When an index is
checked additional fields appear defining the default output file name, file size, and the default number of lines per
page.
The Output Filename and Lines per Page may be edited. Simply type in them to edit or use the arrows to
increase or decrease the number of lines per page.
If the Create Codebook box is checked, the same additional information appears for it. The boxes may also be
edited. To create the files specified, press the Create Files button.
Or choose another tab for more documentary options.
List Options Tab
Use the List Options tab to select print out of the lists of the variable names.
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NLS Investigator Manual
Documentation
When a list is checked additional fields
appear defining the default output file name,
file size, and the default number of lines per
page.
The boxes may be edited. Simply type in
them to edit or use the arrows to increase or
decrease the number of lines per page.
To specify an Output Location, type it in the
box or use the Browse button to browse for
the output locations.
To create the files specified, press the
Create Files button.
Figure 23 Field Widths Tab
Field Widths Tab
Use the Field Widths tab to customize the output files. A field may be excluded with a width of '0' or the width of
the field maybe be changed by typing in a new integer.
Figure 23 to the right displays the default field widths.
To create the files specified, press the Create Files button.
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NLS Investigator Manual
Appendices
Appendices
Appendix 1
CHRR Database Investigator - Main Menu Commands
Menu Components
Command
Description
New Tagset
Open Tagset
Append Tagset
Open a new, blank extract specification file.
Re-open an existing extract specification file.
Re-open an existing extract specification file and
append variables to it.
Save selected variables in an extract specification file.
Save selected variables in a renamed extract
specification file.
Create printable text documentation files.
Close the program.
Shortcut
File
Save Tagset
Save Tagset As
Write Documentation
Exit
Window
Default
Cascade
Tile Horizontal
Tile Vertical
Contents Window
Variables Window
Text/Codebook Window
Reset CHRR Database Investigator windows to the
default arrangement.
"Stack" the child windows in CHRR Database
Investigator.
Horizontally arrange the child windows in CHRR
Database Investigator.
Vertically arrange the child windows in CHRR Database
Investigator.
Switch to the Navigation window.
Switch to the Variable List window.
Switch to the Text/Codebook window.
Extract
Review Tagged
Variables
Extract Tagged
Variables
Review selected variables.
View Case
Close Case
Select one case and view its data values.
Stop viewing the selected case.
Font
Add a Cohort
Delete a Cohort
Change the appearance of text.
May be used to manually install a cohort (dataset).
Removes a cohort from the "Cohort" drop down list and
removes all files and directories for the specified cohort
from the drive. The currently selected cohort cannot be
deleted.
Choose the fields to be displayed in the Variables
Window from a list. Default fields are: Name,
Description, Reference, Question (name), Survey Year,
Area of Interest.
Create an extract with selected variables.
Data
Options
Select Fields
Copyright: The Ohio State University - CHRR
Alt+0
Alt+1
Alt+2
Alt+3
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Appendices
Links
NLS Information
Link to an informative page that lists all of the
supplementary documentation, software, and cohorts
that comprise the National Longitudinal Surveys.
About...
DB Investigator Online
Manual
DB Investigator
Download
Display version information.
Link to this manual that opens in new window
independent of the DB Investigator software.
Link to a download page for the DB Investigator
software and manual.
Help
In addition, to the Command menus above, the Manage Cohorts window contains a register of command under
the File menu.
Manage Cohorts -- Menu Components
Command
Description
Shortcut
Search for
Cohorts
Add
Search the network neighborhood for cohorts (datasets) that are recognized
by the software.
Add a cohort to the Database Investigator. Cohort(s) to add must be
checked.
Remove a highlighted cohort from the Database Investigator. Optionally,
delete files and directories for the highlighted cohort. If you specify 'no' to
deleting the files, this command is the equivalent of unchecking the file
description in the Manage Cohorts window.
Use a Window’s dialogue box to view the path and directory where a cohort
data file resides. Individual cohort must be highlighted.
Leave the Database Investigator software and close it down.
File
Remove
Explore
Exit
Copyright: The Ohio State University - CHRR
NLS Investigator Manual
Appendices
21
Appendix 2
File Names
After selecting one of the options and naming the extract specification file, a three-letter default file extension will
automatically be attached to the name entered. Depending on what data set was originally chosen in the Cohort
field, the file extension for the extracted specification file will be one listed in the Extract File Types below. The
name of the current working file is identified in the CHRR Database Investigator Title Bar (blue bar) as [Tagset:
file-name]. If it is a new file the file name will be "untitled" until it is given a name when the "Extract Tagged
Variables" option is activated.
Extract File Types
The extension depends on the data set used.
*.men
*.boys
*.women
*.girls
*.nlsy79
*.childya
*.nlsy97
Men, extract specification file used to store variables.
Boys, extract specification file used to store variables.
Women, extract specification file used to store variables.
Girls, extract specification file used to store variables.
NLSY79, extract specification file used to store variables.
Child/Young Adult, extract specification file used to store variables.
NLSY97, extract specification file used to store variables.
All files subsequently created in conjunction with the extract file will use the same 8-letter filename, and
depending on the file type to be created, one of the following extensions will be attached.
(tagset_file_name).CDB
(tagset_file_name).DAT
(tagset_file_name).DCT
(tagset_file_name).DOC
codebook print files of the total universe codebook for the selected variables.
extracted data files containing the selected variables.
STATA dictionary file
index print file listing the selected variables with descriptive statistics.
Copyright: The Ohio State University - CHRR
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NLS Investigator Manual
Appendices
Documentation Files
Below is a complete list of files that can be produced when the ‘Write Documentation" option is chosen from the
File component of the Main Menu. Documentation files are given the default extension of .txt. Most of these files
are enormous so if you want to produce them be sure you have enough room on your PC. The "anyword.txt" file
alone is 1.1 Gb!
anyword.txt
Dscrpt_test.txt
Reference.txt
QYear.txt
Question.txt
codebook.txt
varname.txt
Any word in context index.
Area of Interest index
Reference number index.
Survey year index.
Question name list.
Complete codebook.
Variable name list.
Copyright: The Ohio State University - CHRR
NLS Investigator Manual
Index
23
Appendix 3
Sample Files Generated
The following sample extract files were created as a result of Performing an Extract on the file set up in Chapter
4. The files displayed in this section are.
Chld--882ndpreg.CDB
Codebook file for the variables extracted.
Chld--882ndpreg.DCT
Stata Dictionary file for the variables extracted.
Chld--882ndpreg.DOC
Documentation File to Document the Raw Data File (*.DAT)
Chld--882ndpreg.SAS
SAS file.
Chld--882ndpreg.SPS
SPSS file.
Chld--88-2ndpreg.CDB
Figure 24 Codebook File of Extracted Variables
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NLS Investigator Manual
Index
Chld--88-2ndpreg.DCT
Figure 25 Stata Dictionary of the Extracted Variables
Chld--88-2ndpreg.DOC
Figure 26 Documentation File to the Raw Data File
Copyright: The Ohio State University - CHRR
NLS Investigator Manual
Index
Chld--88-2ndpreg.SAS
Figure 27 SAS File
Chld--88-2ndpreg.SPS
Figure 28 SPSS File
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Index
Copyright: The Ohio State University - CHRR