Hypothesis Testing Using SPSS

Unpaired t-test:

  1. Under ‘Variable View’ label your columns as follows:
    1. Column 1= ‘Grouping Variable’ (Ex. Sex)
    2. Column 2= ‘Data Variable’ (Ex. Height)
  2. In ‘Data View’ enter your data as follows:                                                                               

Drug

time

N

2.6

N

5.1

P

3.2

 

  1. Click ‘Analyze’ on the upper toolbar and highlight ‘Compare Means’
  2. Click ‘Independent Samples T Test’
  3. Click on your Grouping Variable (Ex. Sex) and click the arrow to put it into the Grouping Variable box
  4. Click the tab labeled ‘Define Groups’ and type in your 2 group names.  You need to type this exactly as it appears in your data column.  Click ‘Continue’
  5. Click on your Data Variable and click on the arrow to put this into the Test Variable box
  6. Click OK

 

Understanding the Output:

t-statistic
 

p-value
 

 

 

 

 

 

Paired t-test:

  1. Label your columns and enter your data as follows:

Before

After

1

10

6

12

4

8
  1. Click Analyze and highlight ‘Compare Means’ then click on ‘Paired Samples T Test’
  2. Click on the labels in the left box and move to ‘Paired Variables’ box on the right using the arrow.  YOU MUST HIGHLIGHT BOTH COLUMNS FIRST BEFORE CLICKING THE ARROW TO MOVE THEM TO THE ‘PAIRED VARIABLES’ BOX
  3. Click Ok

 

Understanding the Output:

 


p-value
 

t-statistic