Topic summary

Aggregated purity results across four services, with caveats — a second dataset

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

This is a generated summary. It shows the 9 most-liked posts from a topic of 152, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.

h.lindqvistTL26 Sep 2025#3

cohort_watch, post #1: Aggregated purity results across four services, with caveats — a second dataset — setting out what I have, and where I think it stops being reliable. Posting a small dataset on Aggregated purity results across four. It is mine, it is uncontrolled, and the method is stated so it can be discounted appropriately. What I would like is not… Go to post

Combining results from different testing services into one column loses information that matters. Keep the service as a field.

Adding this to the thread rather than to the wiki, because I am not confident enough for the wiki.

31 likes in reply to #1 11mo

w.verhoevenTL26 Sep 2025#9

r.ekstrom, post #5: Aggregated purity results across four: I would want to see the raw numbers rather than the summary before agreeing. Summaries lose exactly the information that would settle this. Go to post

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.

30 likes in reply to #5 11mo

f.yildizTL27 Sep 2025#18

dexa_twice_yearly, post #13: 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. Go to post

The thing about Aggregated purity results across four that took me longest to accept is that a plausible mechanism is not evidence of an effect. It is a reason to look, not a result.

26 likes in reply to #13 11mo

t.tullochTL27 Sep 2025#26

w.verhoeven, post #9: 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. Go to post

Post #23 answers the question as asked. The question underneath it is different.

Nobody has said the unglamorous part of Aggregated purity results across four yet, so: most of the variation is explained by things that are boring to write about and easy to check.

28 likes in reply to #9 11mo

RodriguesTL3Regular7 Sep 2025#33

A codebook describing each field takes twenty minutes and is what makes the file usable by anyone but you. Most shared datasets here do not have one.

If anyone has run this properly I would rather read that than my own guess.

29 likes 11mo

f.danquahTL210 Sep 2025#97

t.tulloch, post #26: Post #23 answers the question as asked. The question underneath it is different. Nobody has said the unglamorous part of Aggregated purity results across four yet, so: most of the variation is explained by things that are boring to write about and easy to check. Go to post

Appreciated. The plain phrasing does more work here than a longer post would.

26 likes in reply to #26 11mo

a.lindqvistTL211 Sep 2025#131

Temporal bias: older data in a dataset might reflect conditions (supplier, formulation, context) that have changed. Newer data is more current.

29 likes 11mo

vial_deskTL3Regular11 Sep 2025#140

Combining results from different testing services into one column loses information that matters. Keep the service as a field.

28 likes 11mo

MJayawardenaTL3Regular11 Sep 2025 · edited#151

Aggregating first-hand accounts does not produce evidence of the kind a trial produces. It produces a description of who chose to post, which is a real thing and a different thing.

A qualification I should have led with rather than closed on.

26 likes 10mo

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Contributing data without breaching anyone's privacyData & Tools › Datasets · 71 replies

This topic was closed 45 days after the last reply. Closing is automatic for quiet topics so that a settled answer does not collect new questions underneath it. If you have a follow-up, open a new topic and link back to this one — that keeps both readable and gives your question its own title.

Moved from Calculators by t.vasquez. Category placement is not obvious from outside and getting it wrong is expected. This topic will get better answers here. The move is recorded in the public log citing R7.

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