Dr. H. Friedman
Using SPSS/PC
(1) Click twice quickly with the left-side of the mouse on the SPSS icon. This gets you
into SPSS for Windows. You will see something that looks like a spreadsheet titled
Newdata. The rows (numbers) are cases, i.e., subjects; the columns are the variables
(VAR).
(2) First you must define the variables. Move your mouse pointer to the first column and
make sure that it is on the word VAR. Click twice quickly with the left-side of the mouse.
(Alternatively, you may select Define Variable... from the Data menu.) Enter a variable
name that is eight characters or less in the Variable Name box (e.g., Usage). The default
variable name VAR00001 is highlighted so that you will be able to write over it. [Note:
SPSS variable names are a maximum of eight alphanumeric characters; they must begin with
an alphabetical character.] You will see four "Change Settings" buttons on the
screen: Type... (to define the type of the variable), Labels... (to define variable and
category labels), Missing Values... (to define a code for missing data), and Column
Format... (width of column and alignment). Type allows you to define the type of data the
variable represents, such as numeric, dollar, date, etc. If your data is numeric, you can
specify the number of digits after the decimal point. For the Usage variable you may use
the numeric type with 0 decimal places and change the width from 8 to 2. The Usage
variable is a single digit (a 1, 2, 3, or 4 will be used to represent level of usage) and
a field of two columns is more than adequate for this variable.
Labels allows you to define long descriptive labels for your variables and/or various
values in your data. These labels will appear on your output. For example, for the Usage
variable, you can use the Variable Label: Coffee usage. To define optional value labels,
enter a value (say, 1) and then enter a value label (Heavy user). Click the Add button.
Then you will be able to enter the remaining value labels (2, medium user, 3, light user,
4, nonuser). When you are finished, click Continue.
Missing Values. If there are missing values in your data, you can define codes for them.
For example, if -1 is your code for a missing value, click on Discrete Missing Values and
type -1 in the first box. (Alternatively, you may wish to use the number 9 as your missing
value code.)
Click on column 2 of the spreadsheet and repeat step (2). Define all the variables in this
manner. (Use the mouse to bring the mouse pointer to any column or row of the
spreadsheet.)
(3) Bring the mouse pointer to row 1 and the first column and enter the data by pressing
the Enter key. Now enter all the data into the datafile. To save your data, choose Save As
from the File menu. Insert your own disk in the a: drive. Choose the a: drive. Give your
data file a name, for example, a:coffee.sav and click OK. When you come back to the
computer another day and wish to use the datafile you saved: Get into SPSS and choose File
- Open - Data and open your file (remember that your file is in the a: drive).
Now you are ready to use SPSS procedures to analyze your data.
(4) Under the Statistics menu, choose Summarize and then choose Frequencies. You are
presented with all your variables. Highlight each variable you wish to analyze, then click
on the > button to add them to a box called Variables. Click on the Statistics button
to select the statistics you wish to see, e.g., mean, median, mode, standard deviation,
etc and click Continue. When you click OK, the results appear in the Output window. This
window will keep the results of all the analyses you will run. The Frequencies procedure
gives you the summary measures you request and also presents the frequency distributions.
If you only wish to see the descriptive statistics themselves, choose Statistics -
Summarize - Descriptives.
(5) To do a t-test, Choose Statistics - Compare Means - Independent Samples T test. Add
test variables to the indicated box, e.g., aroma, intent, overall, price. Add a grouping
variable to the indicated box, e.g., sex, then click on the Define Groups button. Specify
the value 1 (e.g., if 1 represents males) as Group 1 and the value 2 (if 2 represents
females) as Group 2. Click Continue. Then click OK to run the procedure.
(6) To perform a correlation, choose Statistics - Correlate - Bivariate. Choose the
variables you wish to correlate and click OK.
(7) To perform crosstabs, choose Statistics - Summarize - Crosstabs. Decide on your row
variables, your column variables. Click on the Statistics button to choose, say,
Chi-square and Cramer's V statistics, then click Continue. Click the Cells button to get
the observed and the expected frequencies. When you are ready, click OK to run the
crosstabs procedure.
(8) To perform a regression, choose Statistics - Regression - Linear. Highlight the
dependent variable and click on the > button to add it to a box called Dependent.
Highlight the independent variable and click on the > button to add it to a box called
independent. The Method should read Enter. Click OK to run.
(9) To perform a One-way ANOVA, choose Statistics - Compare Means - One-Way ANOVA.
Highlight the dependent variable(s) and click on the > button to add it to a box called
Dependent List. Highlight the group variable and click on the > button to add it to a
box called Factor. You can also click on the Post Hoc... box to perform multiple
comparisons. Click OK to run.
(10) To print your output, select Print from the File menu. To print your input data file,
select Print from the File menu after switching back to the input window [see (11) to
learn how to switch from one window to another].
(11) To go from the Output window to the Input data (Newdata) window (or vice versa) do
one of the following: (a) either click on the visible portion of the window you would like
to get to. You will note that one window almost, but not quite, overlaps the other. Or,
(b) choose the Window menu and click on Newdata to get to the input file or Output to get
to the output file. To see them both, side by side, click on Tile. Cascade means that the
windows overlap; this is the default.
(12) To draw graphs, choose Graphs from the menu. You will note that you have a choice of
various types of graphs including Bar... (barchart), Histogram..., and Scatter... To get a
barchart, select Bar... from the Graph menu. Click inside of the rectangle with word
Simple next to it and then click on the Define box. Insert the variable you wish to
analyze into the Category Axis box by highlighting it and then clicking on the >
button. If you wish, you can add titles and subtitles to the chart by clicking on Titles.
Click OK to run (click Continue and then OK if you are in the Title box). Your output will
appear in something called a Chart Carousel. To get a scattergram, choose Graphs -
Scatter... and define the Y Axis and X Axis variables as above. Click OK to run.
(13) To recode your original variables, choose Transform - Recode... To compute a new
variable from the original variables use Transform - Compute...
To randomly select cases, choose Data - Select Cases...
To calculate Cronbach's alpha coefficient, choose Statistics - Scale - Reliability
Analysis. For quality control charts, choose Graphs - Control...
Sample Questionnaire:
(1) About how many cups of coffee do you drink in a normal day?
___more than 5 cups (heavy user)
___between 3 and 5 cups (medium user)
___about 1 or 2 cups (light user)
___about 0 (non user)
(2) Please try Brand X coffee and rate it on each of the following:
TASTE: ___excellent ___very good ___good ___fair ___poor
AROMA: ___excellent ___very good ___good ___fair ___poor
OVERALL ___excellent ___very good ___good ___fair ___poor
(3) Please indicate the chance that you would buy Brand X coffee?
DEFINITELY WOULD BUY ___ ___ ___ ___ ___ ___
___ DEFINITELY WOULD NOT BUY
(4) How much would you be willing to pay for an eight ounce jar of Brand X coffee?
_______________
(5) The following are necessary for classification purposes:
SEX: ____Male ____Female
AGE: __________
The SPSS variable names one might use for this questionnaire are: USAGE, TASTE, AROMA,
OVERALL, INTENT, PRICE, SEX, AGE.
Sample Data:
1 4 5 4 6 1.08 1 28
1 2 2 3 2 2.45 2 41
2 1 1 1 1 3.00 2 57
2 4 4 4 6 1.78 1 31
3 4 5 4 6 2.06 2 40
3 3 5 4 5 1.88 1 39
4 4 3 4 4 2.95 2 48
4 2 2 3 2 2.78 1 38