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Revisiting: Sample size in a voluntary survey: the selection problem

Data & Tools › Datasets data table confounding site feedback observational data

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Solved by Ridgeway in post #3

Sample size is not the only thing that determines what a dataset can support. Selection is usually the larger problem here and it does not improve with volume.

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r.aldana_pharmdTL4Pharmacist8 Sep 2025#1

Revisiting: Sample size in a voluntary survey: the selection problem — setting out what I have, and where I think it stops being reliable.

I have spent a fortnight trying to pin Sample size down and I want to set out where I have got to, because I suspect the honest answer is duller than the thread this will produce.

What I have: a consistent observation across a small number of cases, collected the same way each time. What I do not have: any controlled comparison, or any reason to think my cases are representative.

The specific question is whether the pattern survives once the obvious confounder is removed. I cannot remove it with what I have.

5 likes 11mo

z.adeyemiTL213 Oct 2025#2

Units in the column header, always, and the same units down the whole column. Mixed units in one field is the commonest defect in shared spreadsheets here.

0 likes 9mo

RidgewayTL3Regular Solution7 Nov 2025#3

Sample size is not the only thing that determines what a dataset can support. Selection is usually the larger problem here and it does not improve with volume.

28 likes 9mo

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