Usage of Rho_A reliability coefficient
Usage of Rho_A reliability coefficient
Hi everyone,
I would like to use the rho_A coefficient as defined in Dijkstra and Henseler(2015) and implemented in PLS3.2.
In a small model with 4 reflexive constructs, I have both rho_A and sqrt(rho_A) in the tables as implemented by PLS3.2. The above reference does not give an idea of the threshold under which a rho_A indicates that a LV is not reliable. And what use does sqrt(Rho_A) have?
One key LV which is causing me headaches has 8 items, a Cronbach alpha of .705, a composite reliability of 0=.403 and a rho_A of .647. How do I analyze such results? Pruning the items only makes things worse (at least regarding the alpha).
All path coefficients leading from it are tstatistics <1.96, meaning that it does not have any effect on the other LV.
BTW, all the other LV have nice and healthy reliability and discriminating coefficients.
Any help appreciated.
Thanks.
I would like to use the rho_A coefficient as defined in Dijkstra and Henseler(2015) and implemented in PLS3.2.
In a small model with 4 reflexive constructs, I have both rho_A and sqrt(rho_A) in the tables as implemented by PLS3.2. The above reference does not give an idea of the threshold under which a rho_A indicates that a LV is not reliable. And what use does sqrt(Rho_A) have?
One key LV which is causing me headaches has 8 items, a Cronbach alpha of .705, a composite reliability of 0=.403 and a rho_A of .647. How do I analyze such results? Pruning the items only makes things worse (at least regarding the alpha).
All path coefficients leading from it are tstatistics <1.96, meaning that it does not have any effect on the other LV.
BTW, all the other LV have nice and healthy reliability and discriminating coefficients.
Any help appreciated.
Thanks.
Xavier Brusset
Professor
Logistics and supply chain management
Toulouse Business School
Professor
Logistics and supply chain management
Toulouse Business School
 Hengkov
 PLS SuperExpert
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Re: Usage of Rho_A reliability coefficient
Hi Xavier,
That I remember the cutoff value of coefficient DijkstraHenseler Rho_A must be > 0.7 as Composite Reliability.
If you do not want to remove the item, you may have to give a little justification there.
You also need to see the value GoF with SRMR and NFI, I think you are a bit of a bad fit model.
Best regards,
That I remember the cutoff value of coefficient DijkstraHenseler Rho_A must be > 0.7 as Composite Reliability.
If you do not want to remove the item, you may have to give a little justification there.
You also need to see the value GoF with SRMR and NFI, I think you are a bit of a bad fit model.
Best regards,

 SmartPLS Developer
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Re: Usage of Rho_A reliability coefficient
Hi Latan,
can you provide a reference that explains how to calculate the NFI for PLS models?
can you provide a reference that explains how to calculate the NFI for PLS models?
Dr. JanMichael Becker, University of Cologne, SmartPLS Developer
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Re: Usage of Rho_A reliability coefficient
Hi Latan,
Thank you for the reply. I have looked at the Dijkstra Henseler reference and they don't mention a cutoff value for Rho_A. If I look at the SRMR given by SmartPLS3.2.3, I get a SRMR for common factor of 0.079 and SRMR for the composite model of 0.053. Are these good values?
Would you mind giving a reference on how to evaluate these criteria for model fit? Also, you speak of NFI. I thought that NFI was purely for SEMML models, ie, LISREL AMOS type models.
Can you please substantiate how such an index can be calculated in PLS?
Thank you for your time and patience.
Regards.
Xavier
Thank you for the reply. I have looked at the Dijkstra Henseler reference and they don't mention a cutoff value for Rho_A. If I look at the SRMR given by SmartPLS3.2.3, I get a SRMR for common factor of 0.079 and SRMR for the composite model of 0.053. Are these good values?
Would you mind giving a reference on how to evaluate these criteria for model fit? Also, you speak of NFI. I thought that NFI was purely for SEMML models, ie, LISREL AMOS type models.
Can you please substantiate how such an index can be calculated in PLS?
Thank you for your time and patience.
Regards.
Xavier
Xavier Brusset
Professor
Logistics and supply chain management
Toulouse Business School
Professor
Logistics and supply chain management
Toulouse Business School
Re: Usage of Rho_A reliability coefficient
Hi everyone,
Does anybody know what a Rho_A value above 1 means and how to interpret it?
Best regards,
Lisa
Does anybody know what a Rho_A value above 1 means and how to interpret it?
Best regards,
Lisa
 cringle
 SmartPLS Developer
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Re: Usage of Rho_A reliability coefficient
A rho_A value above 1 is strange and should not occur. You may revert to Cronbach's alpha in that case.
Prof. Dr. Christian M. Ringle, Hamburg University of Technology (TUHH), SmartPLS
 Literature on PLSSEM: https://www.smartpls.com/documentation
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 Literature on PLSSEM: https://www.smartpls.com/documentation
 Google Scholar: https://scholar.google.de/citations?use ... AAAJ&hl=de

 SmartPLS Developer
 Posts: 950
 Joined: Tue Mar 28, 2006 11:09 am
 Real name and title: Dr. JanMichael Becker
Re: Usage of Rho_A reliability coefficient
It may also indicate that you do not have a valid factor model. A composite model might be better in your case. You should reconsider and reevaluate your measurement approach.
Dr. JanMichael Becker, University of Cologne, SmartPLS Developer
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GoogleScholar: http://scholar.google.de/citations?user ... AAAJ&hl=de
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Re: Usage of Rho_A reliability coefficient
that is amazing post
Graduated from Soran University with First Class Degree with Honours in Computer Science