ONE WAY TO DO AN INDEX WITH SPSS
To begin with, get into SPSS and click on the “analyze” drop-down menu:
Leave the cursor on the “scale” choice and the two choices at the right will appear and you click on “reliability analysis.”
Then, you’ll see another window like this:
This window shows the acronyms associated with each of the questions; you’ve seen this from the first assignment.
Now, from here you want to select the names of the items to be included in your index. You can hold down the shift key
and use the down arrow to select contiguous items. If the items you want to select are not contiguous, you can hold down
the “ctrl” key while you click on the ones you want. Once you have done this, it looks like this:
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Next, you have to choose the right statistics and in this case you click on the “statistics” button and see the following
screen:
Be sure you click on “correlations” and “scale if item deleted” boxes. Now, you can click on “continue” and when you
return to the previous window, click on “OK” and SPSS will run the program for you and produce output like the
following:
Reliability
****** Method 2 (covariance matrix) will be used for this analysis ******
_
R E L I A B I L I T Y
A N A L Y S I S
-
S C A L E
(A L P H A)
Correlation Matrix
ABANY
ABDEFECT
ABHLTH
ABNOMORE
ABPOOR
ABRAPE
ABANY
ABDEFECT
ABHLTH
ABNOMORE
ABPOOR
1.0000
.4182
.3072
.8049
.7868
.4104
1.0000
.6284
.4437
.4452
.6329
1.0000
.3177
.3393
.6030
1.0000
.8157
.4355
1.0000
.4542
ABRAPE
ABRAPE
1.0000
N of Cases =
1776.0
2
Item-total Statistics
Scale
Mean
if Item
Deleted
Scale
Variance
if Item
Deleted
6.3941
6.7314
6.8046
6.4155
6.4358
6.7399
2.5927
3.0833
3.3855
2.5562
2.5536
3.1098
ABANY
ABDEFECT
ABHLTH
ABNOMORE
ABPOOR
ABRAPE
Reliability Coefficients
Alpha =
.8675
Corrected
ItemTotal
Correlation
.7437
.6128
.5126
.7719
.7758
.6066
Squared
Multiple
Correlation
.6996
.5249
.4658
.7392
.7218
.5011
Alpha
if Item
Deleted
.8308
.8541
.8698
.8248
.8240
.8553
6 items
Standardized item alpha =
.8680
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