Test of normality

Questions about the implementation and application of the PLS-SEM method, that are not related to the usage of the SmartPLS software.
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kunalmohan
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Test of normality

Post by kunalmohan »

Hi all,

i wanted to test my data for normality and need to confim which one of the ways is the right one:

1. do i conduct normality test for each "Item" i.e indicator of the constructs, or

2. should I do it for each construct i.e. Latent Variable in my Model for e.g. by importing the LV unstandardised scores from Smartpls output in SPSS


Any help would be greatly appreciated.

Thx in advance.
dibakar
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Post by dibakar »

In my opinion you have to use SPSS to test normality.
kunalmohan
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Post by kunalmohan »

thx for the quick reply. However the question was not about using SPSS. SPSS will be used in both options.

MY question was to test each Item (survey question) for normality or just the Constructs
christian.nitzl
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Post by christian.nitzl »

Hey Kunal,

Some hints, that maybe will help you:

ad 1) Generally, you have to test each and every item (indicator) if the follow a normal distribution. I have often seen that procedure in articles.

ad 2) I would test the indicators unstandardised.

Furthermore, they typically tests which are used (e.g. Kolmogorov-Smirnoff-Test) are to conservative for quasimetric scales. Much better for testing the distribution of your indicators are visual inspections, such as QQ-plots or you look at the ‘kurtosis’ and ‘skewness’. Is the absolute value of the ‘kurtosis’ and ‘skewness’ higher than 1, you can say, your indicator isn’t normal distributed. SPSS is very useful for conduct such a normality test (a german hint for doing that in SPSS: Analysieren → Deskriptive Statistiken → Häufigkeiten unter dem Bereich „Statistiken“ anklicken).

Kind regards,

Christian
kunalmohan
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Post by kunalmohan »

Hi Christian,

Thx for clearing up this issue. Your Answer was excatly what I was looking for.

Best Regards,
Kunal
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