Harman’s one-factor test for common method bias
The sole aim of this tutorial is to teach you how to assess common method bias using Harman’s one-factor test for your study especially when the same measurement instrument is used to collect data for both dependent and independent variables.
How to do this in SPSS?
- In SPSS, click Analyze → Dimension Reduction → Factor, you will be presented with the dialogue box below.
- Move all the items measuring the constructs to the variables: box
- Click on Extraction, select Fixed number of factors and input 1 (see the figure below for more details)
- Click Continue and then OK to view the output.
We are interested in the table below.
Interpretation
If the total variance extracted by one factor exceeds 50%, common method bias is present in your study. There is no problem with common method bias in this data since the total variance extracted by one factor is 30.418% and it is less than the recommended threshold of 50%.