Calculating effect sizeI have a data set of about 2000 patients. There are two groups one with the critical illness and others with known critical illness.
I have done a univariate comparison between the two groups based on a there are age (continuous variable) and a number of other categorical variables like sex or race comorbidities et cetera.
Because of the relatively large dataset most of the differences come back as statistically significant with the values less than 0.01.
The reviewers of my paper however want me to report and interpret standardised effect sizes (Cohan's D or Cramer's V).
It seems to be a pretty simple thing to do it on SPSS.
Cramér’s V - Beginners Tutorial (spss-tutorials.com)
It is possible to do this in JMP? The only documentation I could find online was for doing it in a standard least square model in linear regression
Consumer and Market ResearchContent OrganizationData Blending and CleanupMass CustomizationPredictive Modeling and Machine LearningRe: Calculating effect sizeSo by most of these measures, the association is weak.
Re: Calculating effect sizeManual calculation of Cramer's V from this data from the description below
Cramér's V (ibm.com)
would be 0.01..
Re: Calculating effect sizeThe p-value may be used to assess the strength of the evidence against the null hypothesis (no association or measure is zero). The measure of association is used to assess the strength of the association (similar to measures of correlation). So you have strong evidence that the measure is not zero, but it is a weak association. There is a lot of uncertainty in the response even when you know a given category.
You know how to calculate V yourself from the reply above. What value of V do you get for the same association that you analyzed in the picture above?
Re: Calculating effect size
yes .JMP give these measures for association.
Seems from the help menu that lambda and uncertainty coefficient best suit for nominal data.
The values however are very low for lambda it is mostly 0.0000 even when p value is < 0.001
Since i have not seen reported in literature, is it expected for them to be this low in retrospective clinical research
Re: Calculating effect sizeThe two measures that you asked about are not available in JMP, but many others are available. See the Help entry. Perhaps one of them might satisfy the reviewer.
Re: Calculating effect sizeIt seems to me that the measures of association option available in JMP is what I need
It does not give Cramers V but gives Lambda and un certainty coefficient..which seems to be similar
Measures of Association (jmp.com)
Crosstabs statistics (ibm.com)
Re: Calculating effect sizeyes it is only available as LSM model not in Fit X by Y platform..which is fine. I can use it for cohen's D. Cohen's D is also very simple to calculate by hand.
Problem is with categorical variables..Cramers' V ?
Re: Calculating effect sizeHi Sandeep,
It looks like there might have been some confusion about your question. The Cohen's D effect size measure is simply the difference between the means of the group you compared divided by the pooled standard deviations. While this measure is not directly available in JMP (at least in version 14.1), there is a JMP Add-in that does exactly what you need: Calculate Effect Sizes Add-in .
I'll continue to dig to see if there is something even simpler to address your needs.
Best,
TS
Re: Calculating effect sizeAhhh
so there is no way to get this automated in jmp. Some other marker of effect size may be?
Re: Calculating effect sizeHi @Sandeep123 ,
perhaps this discussion help you calculate it manually if you just need a few estimates.
https://community.jmp.com/t5/Discussions/How-to-get-a-p-value-on-descriptive-statistics-How-to-get-Cramer/m-p/68426/highlight/true#M34835
Ron
Re: Calculating effect sizeHi @Sandeep123 ,
perhaps this discussion help you calculate it manually if you just need a few estimates.
https://community.jmp.com/t5/Discussions/How-to-get-a-p-value-on-descriptive-statistics-How-to-get-Cramer/m-p/68426/highlight/true#M34835
Ron
