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- The data consist of indicators of alcohol and marijuana
usage of 1608
high school students during 2001 as recorded in the Monitoring
The Future (MTF) study which is conducted by the Institute
for Social Research at the University of Michigan.
- More details about the data are available at http://www.icpsr.umich.edu/cgi/archive.prl?study=3088&path=SAMHDA.
- The following variables are included:
- ALCLIFS: On how many occasions have you had alcoholic
beverages to drink in your lifetime?
- ALC12MOS: On how many occasions have you had alcoholic
beverages to drink in the past 12 months?
- ALC30DS: On how many occasions have you had alcoholic
beverages to drink in the past 30 days?
- XMJLIFS: On how many occasions have you used marijuana
in your lifetime?
- XMJ12MOS: On how many occasions have you used marijuana
in the past 12 months?
- XMJ30DS: On how many occasions have you used marijuana
in the past 30 days?
- TICK12MO: Within the last 12 months, how many times
have you received a ticket (or been stopped and warned)
for moving violations?
- ACCI12MO: Within the last 12 months, how many times
you were involved in an accident while driving?
- The raw data are listed in the file select.PSF
in the TUTORIAL
folder.
- The first couple of lines of select.PSF
are shown in the following PSF
window.
- The five indicators are modeled to measure the alcohol
usage (ALCUSAGE)and
marijuana usage (MRJUSAGE).
- Alcohol and marijuana usage are modeled as causes of the
number of moving violations and accidents.
- A path diagram of the model is shown below.
Specifying the complex survey design
- Use the Open
option on the File
menu to load the Open
dialog box.
- Select the PRELIS
data (*.psf) option from the Files
of type: drop-down list box.
- Browse for the file select.PSF
in the TUTORIAL
folder.
- Click on the Open
button to open the select.PSF
in a PSF
window.
- Click on the Survey
Design option on the Data
menu to load Survey
Design dialog box.
- Select the label region
from the Variables
in data: list box.
- Click on the Add
button of the Stratification
variable section.
- Select the label school
from the Variables
in data: list box.
- Click on the Add
button of the Cluster
variable section.
- Select the label newwgt
from the Variables
in data: list box.
- Click on the Add
button of the Design
weight section to produce the following
Survey
Design dialog box.
- Click on the OK
button to return to the PSF
window.
- Click on the Save option on the
File
menu.
Fitting the structural equation model
- Select the New
option on the File
menu to load the New
dialog box.
- Select the Path
Diagram option from the list box on the New
dialog box to load the Save
As dialog box.
- Enter the name SELECT.PTH in the File
name string field.
- Click on the Save
button to open an empty PTH
window.
- Select the Title
and Comments option on the Setup
menu to load the Title
and Comments dialog box.
- Enter the title A Model for Traffic Tickets and
Accidents in the Title
string field.
- Click on the Next
button to load the Group
Names dialog box.
- Click on the Next
button to load the Labels
dialog box.
- Click on the Add/Read
Variables button to load the Add/Read
Variables dialog box.
- Select the PRELIS
System File option in the Read
from file: drop-down list box.
- Click on the Browse
button to load the Browse
dialog box.
- Select the file select.PSF in the TUTORIAL
folder.
- Click on the Open
button to return to the Add/Read
Variables dialog box.
- Click on the OK
button to return to the Labels
dialog box.
- Click on the Add
Latent Variables push button to load the Add
Variables dialog box.
- Enter the label ALCUSAGE in the string
field.
- Click on the OK
button to return to the Labels
dialog box.
- Click on the Add
Latent Variables push button to load the Add
Variables dialog box.
- Enter the label MRJSUAGE in the string
field.
- Click on the OK
button to return to the Labels
dialog box.
- Click on the Add
Latent Variables push button to load the Add
Variables dialog box.
- Enter the label ACCIDENT in the string
field.
- Click on the OK
button to return to the Labels
dialog box.
- Click on the Add
Latent Variables push button to load the Add
Variables dialog box.
- Enter the label TICKETS string field.
- Click on the OK
button to produce the following Labels
dialog box.
- Click on the OK
button to return to the PTH
window for SELECT.PTH.
- Check the Y
check boxes of acci12mo
and
tick12mo respectively.
- Check the Eta
check boxes of ACCIDENT
and TICKETS
respectively.
- Click, drag and drop the labels of the observed variables
one at a time into the PTH
window.
- Click, drag and drop the labels of the latent variables
one at a time into the PTH
window.
- Select the arrow icon on the
Drawing toolbar.
- Click and drag 2 indicator paths from the latent variable
ALCUSAGE
to alclifs
and
alc30ds respectively.
- Click and drag 3 indicator paths from the latent variable
MRJUSAGE
to smjlifs,
xmj12mos
and xmj30ds
respectively.
- Click and drag 1 structural path from the latent variable
ALCUSAGE
to TICKETS.
- Click and drag 1 structural path from the latent variable
MRJUSAGE
to ACCIDENT.
- Click and drag 1 indicator path from the latent variable
ACCIDENT
to acci12mo
and right click the path to set the value fixed to
1.0.
- Click and drag 1 indicator path from the latent variable
TICKETS
to tick12mo
and right click the path to set the value fixed to
1.0.
- Right click the error arrow of acci12mo
and fix the error variance of acci12mo
to 0.
- Right click the error arrow of tick12mo
and fix the error variance of tick12mo
to 0.
- Select the double arrow icon on the Drawing
toolbar.
- Click and drag 1 path between the error arrows of alclifs
and alc30ds.
- Click and drag 1 path between the error arrows of xmj12mos
and xmj30ds
to produce the following PTH
window.
- Select the Build
SIMPLIS Syntax option on the Setup
menu to open the following SPJ
window.
- Click on the Run
LISREL icon on the main toolbar to produce the following
PTH window.
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