SPSS at Ole Miss: Part I
This is the first of a twopart article on SPSS at Ole Miss. In part one after
introducing SPSS and looking at how to activate SPSS on willow and on PC, we
look at an example program of SPSS that performs a ttest. Then, we see how
“SPSS save files” are created by SPSS System. In the following article
we show how the “SPSS save file” created in this part is activated and the
data and information is retrieved from it.
SPSS/PC is completely interactive and users only need to enter their data and
then choose a particular routine to perform a specific procedure from many
that are available to them. To activate SPSS on a PC click on the SPSS icon.
After that, everything is menu driven and SPSS help may be utilized to get help.
To activate SPSS on willow, enter: spss m part1.spss >my.out
In this example part1.spss is the user input to the SPSS
software. If there are no errors, the output (result) from this run will be
saved in my.out as requested by the user. Below is a simple example of SPSS
program copied from willow. Please note that lines containing /**/ are
comments and are not executed. These lines explain the SPSS instructions for
performing the ttest. This file is also located at
/users/local/appl/examples/spss/part1.spss on willow.
set width 80
run name ttest:example from pages 74 of Steel & Torrie
data list /ind 1 dep 47
/* */
/* There are two variables, ind located on col 1 and dep located on col. 47 */
/* */
ttest groups=ind/variables=dep
/* */
/* ttest is performed on var. dep. */
/* */
statistics all /* Generate all the statistics available to ttest.*/
/* begin reading data */
begin data
1 57.8
1 56.2
1 61.9
1 54.4
1 53.6
1 56.4
1 53.2
2 64.2
2 58.7
2 63.1
2 62.5
2 59.8
2 59.2
end data /* This line signals the end of the input data */
/* The following 2 lines create two special SPSS files that */
/* may be used by another program to perform more analysis */
export outfile=myportfile
save outfile='tdisk.sav'.
The last two lines of the above program create a binary data set called
“tdisk.sav”. We will talk about how to activate this SPSS save file and
retrieve data from it in the next article. Following result is generated
when the above SPSS program is executed:
Variable of Cases Mean SD SE of Mean

DEP
IND 1 7 56.2143 3.002 1.135
IND 2 6 61.2500 2.302 .940

Mean Difference = 5.0357
Levene's Test for Equality of Variances: F= .019 P= .893
ttest for Equality of Means 95%
Variances tvalue df 2Tail Sig SE of Diff CI for Diff

Equal 3.34 11 .007 1.506 (8.350, 1.721)
Unequal 3.42 10.90 .006 1.473 (8.282, 1.789)

Continue to SPSS at Ole Miss: Part II.
