Factor analysis and PLS

Questions about the implementation and application of the PLS-SEM method, that are not related to the usage of the SmartPLS software.
Post Reply
misu02ab
PLS Junior User
Posts: 3
Joined: Wed Mar 07, 2007 5:46 pm
Real name and title:

Factor analysis and PLS

Post by misu02ab »

Hi,

I have a question regarding PLS and factor analysis

To check the dimensionality of my latent constructs, I have performed a factor analysis in SPSS. The factor analysis in SPSS found 8 different factors, which is conceptually correct. Furthermore, the factors were checked by Cronbach's Alpha.

When I use these 8 factors in SmartPLS, one of the factors (latent constructs) do not have significant factor loadings from none its indicators.

Could someone explain to me, why this is the case?

To my understanding the PLS technique is partly a factor analysis, so one could expect to have the same dimensions in PLS as in a SPSS factor analysis…

Best regards
Michael
User avatar
Diogenes
PLS Super-Expert
Posts: 899
Joined: Sat Oct 15, 2005 5:13 pm
Real name and title:
Location: São Paulo - BRAZIL
Contact:

Post by Diogenes »

Hi Michael,

do you have used extraction with common factor or principal components? sometimes the first is better for this porpose.

rotation was oblique? sometimes the last factors show this kind of problem because, in fact, they have lower loadings than the first ones.

Best regards.
Bido
Last edited by Diogenes on Mon Jan 07, 2008 7:58 pm, edited 1 time in total.
misu02ab
PLS Junior User
Posts: 3
Joined: Wed Mar 07, 2007 5:46 pm
Real name and title:

Post by misu02ab »

Hi Bido,

I have used Principal Component as extraction method and Varimax rotation with Kaiser Normalization. I have tried other extraction methods, which gives a somehow different constellation of the latent constructs (with only 6 constructs instead of the conceptually 8).

I am not sure if I understand, what you mean by: “Sometimes the last factors show this kind of problem because, in fact, they have lower loadings than the first ones”…

Most of all, I am looking for a theoretically explanation to why the difference in the results?

Many thanks

-Michael
User avatar
Diogenes
PLS Super-Expert
Posts: 899
Joined: Sat Oct 15, 2005 5:13 pm
Real name and title:
Location: São Paulo - BRAZIL
Contact:

Post by Diogenes »

Hi Michael,

In EFA, usually, even after rotation, the first factors have more indicators and bigger loadings than the last factors. Remembering that all factors have loading in all indicators.

When we translate this factors as measurement model in PLS, usually we connect the factors with the indicators that had bigger loading in EFA, but now, the LV will be estimated with only these indicators. If the last factors had lower loadings could happen the problem that you are reporting.

Just thinking..
Best regards
Bido
misu02ab
PLS Junior User
Posts: 3
Joined: Wed Mar 07, 2007 5:46 pm
Real name and title:

Post by misu02ab »

Hi Bido,

Now I understand. :-)

That seems like a good reasonable explanation.

Thank you a lot!

Best regards
Michael
viswadatta
PLS Expert User
Posts: 139
Joined: Wed Jul 05, 2006 1:43 pm
Real name and title:
Location: Coimbatore, India

pls vs factor analysis

Post by viswadatta »

PLS is CFA, while factor analysis usually refers to EFA. In factor analysis the end result gives the components of each factor. In PLS we assume it apriori and also check for construct validity.
Post Reply