# Step - by - Step Analysis of SPSS Correlation Procedure by vasana

VIEWS: 0 PAGES: 5

• pg 1
```									                                                                     Office of Information Technology      1

ANALYZING DATA IN SPSS 13.0 USING CORRELATION

Tips before you begin:
•   Make sure your data set is open before attempting to run any analyses.
•   During analyses, right click on terms or buttons in the dialog boxes to learn about their functions.
•   The Help button in the dialog boxes maybe clicked at any time during analyses for more
information on that particular procedure.
•   Click the Reset button to clear the dialog box and begin a fresh analysis.
•   Click the Cancel button to exit that dialog box without saving changes.

Choose a Procedure:
•   Bivariate Correlations
•   Partial Correlations
•   Distances

BIVARIATE CORRELATIONS
In Bivariate Correlations, the relationship between two variables is measured. The degree of
relationship (how closely they are related) could be either positive or negative. The maximum number
could be either +1 (positive) or -1 (negative). This number is the correlation coefficient. A zero
correlation indicates no relationship.

Examples. Are a student’s grade and the amount of studying done correlated? You might find that
these variables are positively correlated. Or say, is the number of games won by a basketball team
correlated with the average number of points scored per game?

Procedure
1. On the menu bar of the SPSS Data Editor window, click Analyze > Correlate > Bivariate…

2. Select one or more variables that you want to analyze by clicking on the variable labels in the
Bivariate Correlations dialog box. To select multiple variables, hold down the Ctrl key and choose

Indiana State University, 2005
Office of Information Technology      2

the variables you want. Click on the arrow button to add selected variables to the Variables
window.

List of                                                                                                  Empty
Variables                                                                                                Variables
Window

Right arrow
selected
variable(s)

3. Check the type of correlation coefficients that you require (Pearson for parametric, and Kendall’s
tau-b and Spearman for non-parametric).

4. Click on the Options… button to
select statistics, and to control the
treatment of missing values. Click
on the Continue button.

5. Click the OK button in the Bivariate Correlations dialog box to run the analysis. The output will be
displayed in a separate SPSS Viewer window.

PARTIAL CORRELATIONS
The Partial Correlations procedure computes partial correlation coefficients that describe the linear
relationship between two variables while controlling for the effects of one or more additional variables.
Correlations are measures of linear association. Two variables can be perfectly related, but if the
relationship is not linear, a correlation coefficient is not a proper statistic to measure their association.

Indiana State University, 2005
Office of Information Technology     3

Example. Is there a relationship between healthcare funding and disease rates? Although you might
expect any such relationship to be a negative one, a study reports a significant positive correlation: as
healthcare funding increases, disease rates appear to increase. Controlling for the rate of visits to
healthcare providers, however, virtually eliminates the observed positive correlation. Healthcare
funding and disease rates only appear to be positively related because more people have access to
healthcare when funding increases, which leads to more reported diseases by doctors and hospitals.

Procedure
1. On the menu bar of the SPSS Data Editor window, click Analyze > Correlate > Partial…

2. Select one or more variables that you want to analyze by clicking on the variable labels in the
Partial Correlations dialog box. Also select one or more numeric control variables. To select
multiple variables, hold down the Ctrl key and choose the variables you want. Click on the
respective arrow buttons to add selected variables to the Variables and Controlling for windows.

Empty
List of                                                                                                   Variables
Variables                                                                                                   Window

Empty
Controlling
for Window
Right arrow
buttons to
variable(s)

Indiana State University, 2005
Office of Information Technology      4

3. Click on the Options… button to
select statistics, and to control the
treatment of missing values. Click
on the Continue button.

4. Click the OK button in the Partial Correlations dialog box to run the analysis. The output will be
displayed in a separate SPSS Viewer window.

DISTANCES
This procedure calculates any of a wide variety of statistics measuring either similarities or
dissimilarities (distances), either between pairs of variables or between pairs of cases. These similarity
or distance measures can then be used with other procedures, such as factor analysis, cluster
analysis, or multidimensional scaling, to help analyze complex data sets.

Example: Is it possible to measure similarities between pairs of automobiles based on certain
characteristics, such as engine size, MPG, and horsepower? By computing similarities between autos,
you can gain a sense of which autos are similar to each other and which are different from each other.

Procedure
1. On the menu bar of the SPSS Data Editor window, click Analyze > Correlate > Distances…

2. Select one or more variables that you want to analyze by clicking on the variable labels in the
Distances dialog box. Optionally, select a single string variable for the Label Cases by window. To
select multiple variables, hold down the Ctrl key and choose the variables you want. Click on the
respective arrow buttons to add selected variables to the Variables and Label Cases by windows.

Indiana State University, 2005
Office of Information Technology      5

Empty
List of                                                                                                     Variables
Variables                                                                                                     Window

Empty
Label Cases
by Window
Right arrow
buttons to
variable(s)

3. Select the type of distance to compute and the type of measure that you require.

4. Click on the
Measures… button to
explicitly define options
for dissimilarity or
similarity measures.
Click on the Continue
button.

5. Click the OK button in the Distances dialog box to run the analysis. The output will be displayed in
a separate SPSS Viewer window.