any goodness index

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needpls
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any goodness index

Post by needpls »

hi

smart pls have any goodness index?


how we can evaluate our model ? in amos and lisrel we see many indexes like NFI,GFI and ....
but in pls???
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Hengkov
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Post by Hengkov »

Hi,
For GoF Model in PLS compute with formula = SQRT Average Communality x Average R-Square, OK.
Regards,
Hengky
needpls
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Post by needpls »

hii

thx for your answer

please explain that how i can find this measures in pls?


1-where is Average Communality and where is Average R-Square?

2-what is the mean of SQRT?

3-Q2 is not goodness index???


best regards
kristianak
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Post by kristianak »

Hi needpls,

You find communality, AVE and R^2 in the report after running the PLS algorithm.

SQRT is square root.

Q2 is not Goodness of Fit.

According to Vinzi, Trinchera, Amato (2010), pp. 58-60, GoF then is:

GoF=√(Com×(R^2 ))=√(AVE×(R^2 ))

Com = average communality, R^2 is average R^2.
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Post by needpls »

thxxxxxxxxxx so much kristian . u helped me soooo mcuh.


can i ask one another thing??

what is good GOF? in lisrel for example GIF must be greater than .9 or NFI must be greater .9 ? but GOF must be greater ...????

best regards
needpls
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Post by needpls »

hi

another question

for average R2 i must concider only endogenous constructs or all constructs?

for example i have 6 construct and one endogenous so i have 5 R2 equal to 0 and 1 equal to .5 .if i use only one R2 my avrerage is .5 else is .08

which is true? .5 or .08???

bets regards
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Hengkov
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Post by Hengkov »

Hello Hesw,
According to Latan and Ghozali (2012a): GoF 0.10 (Small), 0.25 (Medium) and 0.36 (Large).
Latan, H and Ghozali, I. (2012a). Partial Least Squares: Concept, Technique and Application using Program SmartPLS for Empirical Research, BP UNDIP.

Or

According to Latan and Ghozali (2012b): GoF 0.35 (Small), 0.50 (Medium) and 0.61 (Large).
Latan, H., and Ghozali, I. (2012b). Partial Least Squares: Concept and Application Path Modeling using program XLSTAT-PLS for Empirical Research, BP UNDIP.
GoF greather is good.
Next, because you have only one endogenous variable, average R-square = R-square one endogenous variable, OK.
Regards,
Hengky
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Post by Joules »

Thanks for the literature tip!! Btw, do you know where you can get them? I searched for them but couldn't get a hold of any article.

So, I read Tenenhaus et al. (2005) and Henseler/Sarstedt (2012) today and according to them (especially the former) it's as follows:

Average communality = You add up all squared indicator-construct correlations and divide them by the total number of indicators in your model.
Actually it's the sum of [AVE(i) divided by the number of indicators of construct (i)] over all constructs in your model and then divided by the total number of indicators.
Or simply 1/n*sum [AVE(i)]. But somehow, in my case, the "simplified" mean of the AVE taken from the SmartPLS spreadsheets and the "correct" way to calculate it differed a bit. Maybe due to fewer decimals...

Example: construct 'Affect' has indicator correlations of aff_x1=0,869, aff_x2=0,789 and aff_x3=0,923. And another one 'Intention' has int_x1=0,846, int_x2=0,799, int3_x3=0,856.
Then, the average communality would compute as:
1/6 * (0,869²+0,789²+0,923²+0,846²+0,799²+0,856²) = 0,719.
The AVE (in a standardized case) for 'Affect' would be 1/3*(0,869²+0,789²+0,923²0,743)=0,743.

Average R² = mean of all endogenous variables' R²

Given the above example, if an average R² would be 0,234 the GoF would compute as: Square Root (0,719*0,234) = 0,41.

Am I wrong?

Henseler/Sarstedt (2012) have good overview table with results you can reproduce.

Henseler/Sarstedt (2012): Goodness-of-fit indices for partial least squares path modeling, in: Springer.
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Post by needpls »

hi
Hengkov thx so much

and Joules i think that it is correct and u can see AVE in repport no need to compute it with hand.


best regards
Joules
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Post by Joules »

needpls wrote:hi
Hengkov thx so much

and Joules i think that it is correct and u can see AVE in repport no need to compute it with hand.


best regards
I know, but for some reason the average AVE differs from the mean of the sum of all squared indicator correlations - at least in my model.
There, i get an average AVE of 0,780 whereas the mean of the sum of all squared indicator correlations show 0,783. Does anyone know what the reason for that is?
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Post by minutolo »

I had an article accepted pending my putting in information on fit indices. This stream has helped a lot.....THANKS!
needpls
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Post by needpls »

Hengkov wrote:Hello Hesw,
According to Latan and Ghozali (2012a): GoF 0.10 (Small), 0.25 (Medium) and 0.36 (Large).
Latan, H and Ghozali, I. (2012a). Partial Least Squares: Concept, Technique and Application using Program SmartPLS for Empirical Research, BP UNDIP.

Or

According to Latan and Ghozali (2012b): GoF 0.35 (Small), 0.50 (Medium) and 0.61 (Large).
Latan, H., and Ghozali, I. (2012b). Partial Least Squares: Concept and Application Path Modeling using program XLSTAT-PLS for Empirical Research, BP UNDIP.
GoF greather is good.
Next, because you have only one endogenous variable, average R-square = R-square one endogenous variable, OK.
Regards,
Hengky

hi
can u say me how can i find this articles?
lyudmi
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Goodness of Fit - Rule of thumb

Post by lyudmi »

Hi, guys.

I am a little bit confused by the two classifications of GoF given by:

1) Latan and Ghozali (2012a):

GoF >= 0.10 (Small)
GoF >= 0.25 (Medium)
GoF >= 0.36 (Large)

and

2) Latan and Ghozali (2012b):

GoF >= 0.35 (Small)
GoF >= 0.50 (Medium)
GoF >= 0.61 (Large)

I have a model which GoF is 0,279. According to the first article the model has a Medium GoF and according to the second one - a Small one.

And here is my question - when reporting the results of my study (Master thesis), should I state that the model has a Medium or a Small Goodness of Fit?



And one more question in that direction:

My model consists of seven constructs experiencing the following R Squares:

Construct 1: 0,019
Construct 2: 0,365
Construct 3: 0,095
Construct 4: 0,083
Construct 5: 0,343
Construct 6: (no value)
Construct 7: 0,241

And Communality:

Construct 1: 0,425
Construct 2: 0,617
Construct 3: 0,247
Construct 4: 0,562
Construct 5: 0,169
Construct 6: 0,367
Construct 7: 0,463

So, I computed the avr_Communality and avr_R_Squared and take the square root out of avr_Communality*avr_R_Squared. That is how I found GoF.

And here is my question:

When I calculate the avr for R_Square, should I sum all of the values for the seven constructs, including 0 for the missing value of Construct 6, and then divide it by 7 or should I exclude Construct 6 from both of the calculations of avr_Communality and avr_R_Squared and work only with the rest 6 constructs?

Thank you in advance :)
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Hengkov
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Post by Hengkov »

Hi Lyudmi,
This is My books, no article.
Your communality construct very low, please check outer loading must higher than 0.6 or 0.7.
Next, construct 6, R-square = 0 it's mean this construct is exogenous. You just compute R-square endogenous for asses GoF.

Because PLS not provide any goodness of fit indices, Tenenhaus et al. (2004) create formula for compute GoF in PLS:
SQRT average Com * average R-squares
But Tenenhaus et al. (2004) not provide cut-off value for interpretation this GoF similar CB-SEM such, RMSEA < 0.8, CFI > 0.95, TLI > 0.90 etc.

We create rule of thumb similar effect size and q-predictive relevance for GoF above:
The basic idea and illustration below:
Communality / AVE recommendation Fornell and Larcker (1981) = 0.50
R-squares recommendation Hair et al. 0.25 (weak), 0.50 (moderate) and 0.75 (strong), so Latan dan Ghozali (2012b) create:
GoF small : SQRT 0.5 * 0.25 = 0.35
GoF medium: SQRT 0.5 * .50 = 0.50
GoF large : SQRT 0.5 * 0.75 = 0.61

GoF is important issue for develop in PLS.

References:
Fornell, C., and Larcker, D.F. 1981. “Evaluating Structural Equation Models with Unobservable Variables and Measurement Error,” Journal of Marketing Research (18:1), pp. 39-50.

Hair, J. F., Ringle, C. M., and Sarstedt, M. 2011. “PLS-SEM: Indeed A Silver Bullet,” Journal of Merketing Theory and Practice (19:2), pp. 139-150.

Latan, H., and Ghozali, I. 2012a. Partial Least Squares: Concept, Technique and Application SmartPLS, BP UNDIP.

Latan, H., and Ghozali, I. 2012b. Partial Least Squares: Concept and Application Path Modeling using XLSTAT-PLS, BP UNDIP

Tenenhaus, M., Amato, S., and Esposito Vinzi, V. 2004. “A global goodness-of-fit index for PLS structural equation modeling,” Proceedings of the XLII SIS Scientific Meeting, Vol. Contributed Papers, CLEUP, Padova, pp. 739–742.

Best Regards,
Hengky
lyudmi
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Post by lyudmi »

Thank you very much for the fast reply Hengky!

However, I want to ask you a couple of other things. You say:

"Next, construct 6, R-square = 0 it's mean this construct is exogenous. You just compute R-square endogenous for asses GoF. "

This means that the average Comunality should also be computed only for endogenous constructs (excluding Construct 6 from the calculation of avr_Communality), right?

Then you say:

"Communality / AVE recommendation Fornell and Larcker (1981) = 0.50"

meaning that both of them should be greater than 0.50 to be considered significant, right?


Concerning the above things, my model (a reflective one) and my data:

Communality
Construct 1: 0,425 < 0.50
Construct 2: 0,617 O.K.
Construct 3: 0,247 < 0.50
Construct 4: 0,562 O.K.
Construct 5: 0,169 < 0.50
Construct 6: 0,367 < 0.50
Construct 7: 0,463 < 0.50

Average variance extracted (AVE)
Construct 1: 0,425 < 0.50
Construct 2: 0,617 O.K.
Construct 3: 0,247 < 0.50
Construct 4: 0,562 O.K.
Construct 5: 0,169 < 0.50
Construct 6: 0,367 < 0.50
Construct 7: 0,463 < 0.50

R Sqrd
Construct 1: 0,019 <0.25
Construct 2: 0,365 0.25< weak <0.50
Construct 3: 0,095 <0.25
Construct 4: 0,083 <0.25
Construct 5: 0,343 0.25< weak <0.50
Construct 6:
Construct 7: 0,241 <0.25

Construct | Nr. of items | Mean | Standard deviation
Construct 1: 9 | 2,56 | 1,06
Construct 2: 4 | 2,42 | 1,32
Construct 3: 15 | 1,99 | 0,77
Construct 4: 4 | 3,99 | 0,88
Construct 5: 20 | 4,37 | 1,68
Construct 6: 10 | 3,59 | 1,19
Construct 7: 8 | 2,12 | 1

Squared Correlations among Constructs
sqr_AVE | C1 | C2 | C3 | C4 | C5 | C6 | C7
0,181 | 1,000
0,380 | 0,352 | 1,000 |
0,061 | 0,005 | 0,024 | 1,000 |
0,316 | 0,019 | 0,010 | 0,017 | 1,000 |
0,029 | 0,002 | 0,005 | 0,213 | 0,012 | 1,000 |
0,135 | 0,003 | 0,004 | 0,095 | 0,083 | 0,235 | 1,000 |
0,214 | 0,219 | 0,026 | 0,008 | 0,000 | 0,001 | 0,006 | 1,000

Can I do something to improve my model and results? Can I say that the model is reliable (GoF=0.334)?

Greetings,

Lyudmil
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