Kurtosis and Skewness coefficents and ANOVA

Lolo

New Member
#1
Hello,
A friend of mine told me that despite my variable is not ditributed normally, I am allowed to do an ANOVA if both Kurtosis and Skewness coefficents are between -3 and 3.
Do you confirm that?

Thanks for your help
 
E

elnaz

Guest
#2
hello
not at all
when i see my data are not normal 1) i use cox-box transformation or 2) i use non parametric test
i advice you do like me
i dont do that at all
Best regards
Elnaz
 

Lolo

New Member
#3
Thanks a lot.
I want to do a non parametric test with 3 factors. I have been said to do a Kruskall-Wallis test, but this is for 1 factor, isn´t it?
 
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elnaz

Guest
#4
Hello
your welcome , but about your second question :
what is your intent about factor ?
is factor for you , population?
if your intent is that you have three population and you want to compare them .
yes ,Kruskall-Wallis test is true.
please ,tell me what is your intent about factor?
if your intent is not population please tell me about your data and your aim in analysis.
 
Last edited by a moderator:

Lolo

New Member
#5
Hello Elnaz,
Thanks very much for your help.
Do you know if a non-parametric test with 3 factors (=2 studied factors + 1 controlled one) does exist?
Regards
 

Lolo

New Member
#6
(Sorry Elnaz, I didn’t see your reply before sending my latest message!!)

This is the aim of my study:
I am studying the post harvest shelf-life of melon fruits, according to the melon variety and the duration of storage (in a cold chamber)
I want to:
- find the varieties that show the longer shelf life
- show the fruit quality loss all along the storage
- if possible : find the maximum shelf-life for each variety.


So I made a split-plot design trial with 2 blocks (referring to the position of the fruit)
I made several measurements referring on fruit quality (weight loss, external and internal appearance, firmness...), which are the variables of my analysis.

What I call "factor" is what I made vary during the experiment. It is to say: the melon variety (I tested 9 different varieties), the storage duration (1 day, 5 days, 10 days...) and the block (which is a factor with a random effect)

My datas are in the following table:

--------------------------------------------------------------------------
Storage Variety Block Weight loss Appearance (mark) ...
--------------------------------------------------------------------------1 day No1 No1
No2
1 day No2 No1
No2
1 day No3 No1
No2
1 day … No1
No2
5 days No1 No1
No2
5 days No2 No1
No2
5 days No3 No1
No2
5 days … No1
… No2
--------------------------------------------------------------------------

Since some variables (for example Appearance) doesn’t follow a normal distribution and given that I didn’t find any suitable transformation for them, I have to do a non-parametric test with 3 factors (= storage, variety, block)

Do you understand my problem?

Best regards