-Transform
items that need to be reversed scored
-Run
frequencies for each item
Analyze…Descriptive
Statistics…Frequencies…Move variables into Variable(s) window…OK
Look
for impossible values
Analyze…Descriptive
Statistics…Frequencies…Move variables into Variable(s) window…select Statistics…check
off Mean, Median, Standard Deviation, and Skewness…Continue…OK
[make sure you uncheck “Display frequency tables”]
Look
for skewed items
Analysis
1:
After you access or enter your data file, do the following:
Click
on:
qAnalyze;
qData
Reduction;
qFactor.
Then,
select variables for your factor analysis as usual.
At
the Factor Analysis box:
qClick
on Descriptives;
qClick
in the box next to Coefficients;
qClick
in the box next to KMO and Bartlett’s test of sphericity;
qClick
on Continue.
At
the Factor Analysis box:
qClick
on Extraction;
qSelect
Principal components in the Method box (¯);
qClick
in the box next to Scree Plot;
qChange
Maximum Iterations for Convergence to 50;
qClick
on Continue.
At
the Factor Analysis box:
qClick
on Rotation;
qConfirm
that “no rotation” is selected;
qClick
on Continue.
At
the Factor Analysis box:
qClick
on Options;
qClick
in the box next to Sorted by size;
qClick
on Continue
Run
the first analysis.Determine the
number of factors with the number of eigenvalues
greater than one.Select two or more
other model dimensionalities to consider in the search for the appropriate
number of factors.
Analysis
2:
Rerun analysis (1) above with the same settings except for the following
changes:
qIn
the Descriptives box, deselect “KMO and Bartletts
test.”
qIn
the Extraction box, select Maximum likelihood in the Method box
(¯),
set the “number of factors” equal to
the # you have decided to test for, and deselect “Scree
plot.”
Analysis
3:
Rerun analysis (2) above with the same settings except for the following
changes:
qIn
the Extraction box, set the “number of factors” equal to an alternate #
of factors that you wish to examine. (Results from analyses 1 through 3
help us to decide how many factors we want)
Analysis
4:
Rerun analysis (3) above with the same settings except for the following
changes:
qIn
the Descriptives box, deselect “Initial
solution” and “Coefficients.”
qIn
the Extraction box, set the “number of factors” equal to the # of factors
you have decided on and deselect “unrotated factor
solution.”
qIn
the Rotation box, select “Varimax” if you think
the factors are not correlated; select "Direct Oblimin" if you think the
factors are correlated.
Item
analysis for each factor
Inter
item correlations
Item
criterion correlations
Alpha
if item removed
Over
all coefficient alpha