topic Re: How to Maintain Proportion Balance when Using Subset with Stratify? in Discussions

How to Maintain Proportion Balance when Using Subset with Stratify?

Thierry_S — Tue, 03 Jul 2018 01:35:14 GMT

Dear JMP Community,

I have used successfully the Stratify option when creating subset tables when the stratifying variable has balanced proportions (e.g. 50% Male and 50% Female).

Now, I need to create a table subset where the stratifying variable is "unbalanced" (e.g. 25% Male and 75% Female). When I execute the Subset with stratification on Gender, the subset table returns 50% Male and 50% Female which is not representative. Hence my question: is there a method to maintain Proportion Balance when using the Subset command with Stratify?

Thank you for your help.

Sincerely,

Re: How to Maintain Proportion Balance when Using Subset with Stratify?

Dan_Obermiller — Tue, 03 Jul 2018 02:23:09 GMT

Which version of JMP are you using? I cannot reproduce this behavior in version 14. Make sure you have the dialog completed properly, too.

Re: How to Maintain Proportion Balance when Using Subset with Stratify?

Thierry_S — Tue, 03 Jul 2018 15:57:58 GMT

Hi Dan,

Thanks for looking into my issue. I use JMP 13.1.0 following the same procedure as depicted in your screen capture.

Let me create a dummy file to share with you.

Best regards,

Re: How to Maintain Proportion Balance when Using Subset with Stratify?

Thierry_S — Tue, 03 Jul 2018 16:07:07 GMT

Dan,

Here is the MASTER table and SUBSET table showing the problem I have with the Stratification option

MASTER: 77% FEMALE and 23% MALE (see attached)

SUBSET: 50% FEMALE and 50% MALE (see attached)

Re: How to Maintain Proportion Balance when Using Subset with Stratify?

mikedriscoll — Tue, 03 Jul 2018 16:20:11 GMT

I don't think I've ever used random w/ sample size in conjunction with stratify. Is that whjat you're intending, or did you want sampling rate? Sampling rate gives me 129 results, groups split by 100 and 29.

Re: How to Maintain Proportion Balance when Using Subset with Stratify?

Thierry_S — Tue, 03 Jul 2018 16:24:50 GMT

Hi Mike,

Yes it is my intention: I would like to select 100 patients to conduct a pilot experiment. But, I just checked the Sampling Rate method and it does not have the issue so I will look into that method instead.

Best regards,