I hope that someone can help clarify some interesting output I came across from a Factor Analysis that I just conducted. I have a 24-item instrument that I used Principal Axis Factoring for. By default, SPSS suggested that there were 5 factors based on the eigenvalue greater than 1 rule. I then tried to run the same procedure but altered the number of factors to be extracted to 3. The eigenvalues for the 3-factor solution were not the same values as the first 3 eigenvalues from the 5-factor solution (all values are based on prerotation). The values are close but shouldn't they be identical given that factors are extracted ortogonally? Thanks!

Kris