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OldGugga
Level II

group matching (case control matching?)

how do i use JMP to equalize or match 6 groups of children on age, for a 3 way ANOVA? the groups range in n from about 30 to 200. i would prefer not to use child age as a covariate in the analysis.

2 REPLIES 2
Kevin_Anderson
Level VI

Re: group matching (case control matching?)

Hi, OldGugga!

 

There can be dangerous Rodents Of Unusual Size in the Fire Swamp of vaguely-posed statistical questions like yours, but I will boldly try to help you in spite of knowing nothing about what you're trying to do or how the experiment you're analyzing was designed or performed.

 

A titan, George Edward Pelham Box FRS has an attributed quote about variation in experiments that goes "Block what you can, randomize what you cannot."  You may be able to block-align the groups of Age and proceed with your analysis.  But, be aware that blocking can harm the sensitivity of the analysis in the presence of block-treatment interactions, which with Age you may indeed have.   You can check for this in the analysis.  And it would be better if your experiment had been designed as a Randomized Block Design in the first place...

 

You might be well served by seeking professional help and consulting with a statistician.

 

Good luck!

OldGugga
Level II

Re: group matching (case control matching?)

thank you sincerely for your bold reply.
a trusted statistician suggested covarying on S age. i see problems in that but there could be problems in any analysis approach
i have to think about this
again thank you