Posting this under the heading it deserves: Sample size in a voluntary survey: the selection problem Everything below is what sits behind that. Posting the method first, because I know what the first three replies will otherwise be. Column: C18, 2.1 x 100 mm, 1.7 um Mobile phase: 0.1% TFA in water / 0.1% TFA in acetonitrile Gradient: 8% to 62% organic over 33 minutes Detection: 220 nm Injection: 6 uL Sample: retatrutide, reconstituted to 1.0 mg/mL, injected within an hour The main peak integrates at 98.2% of total area. There is a small feature on the trailing edge that I cannot decide is a shoulder or a baseline artefact, and that is what I am actually asking about.

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Sample size in a voluntary survey: the selection problem

Data & Tools › Datasets observational data data table site feedback

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Solved by l.dziedzic in post #2

Reproducibility: if sharing data, include enough context (compound, dose, timeframe, method) that someone reading it understands what it represents.

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b.vanheckeTL2 Moderator26 Aug 2024#1

Posting this under the heading it deserves: Sample size in a voluntary survey: the selection problem Everything below is what sits behind that.

Posting the method first, because I know what the first three replies will otherwise be.

Column: C18, 2.1 x 100 mm, 1.7 um
Mobile phase: 0.1% TFA in water / 0.1% TFA in acetonitrile
Gradient: 8% to 62% organic over 33 minutes
Detection: 220 nm
Injection: 6 uL
Sample: retatrutide, reconstituted to 1.0 mg/mL, injected within an hour

The main peak integrates at 98.2% of total area. There is a small feature on the trailing edge that I cannot decide is a shoulder or a baseline artefact, and that is what I am actually asking about.

6 likes 23mo

l.dziedzicTL2 Moderator Solution31 Oct 2024#2

Reproducibility: if sharing data, include enough context (compound, dose, timeframe, method) that someone reading it understands what it represents.

11 likes 21mo

n.lehtinenTL2 Moderator18 Dec 2024#3

b.vanhecke, post #1: Posting this under the heading it deserves: Sample size in a voluntary survey: the selection problem Everything below is what sits behind that. Posting the method first, because I know what the first three replies will otherwise be. Column: C18, 2.1 x 100 mm, 1.7 um Mobile phase: 0.1% TFA in water / 0.1% TFA in acetonitrile Gradient: 8%… Go to post

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

31 likes in reply to #1 19mo

a.ibarraTL2 Moderator29 Jan 2025#4

I read the opening post twice before replying, because I had assumed the opposite.

How to contribute: if you have longitudinal data you want to add, the format is simple: date, measurement, context. Contact the maintainer of the specific dataset.

0 likes 18mo

e.kimaniTL2 Moderator10 Mar 2025 · edited#5

I disagree with the reply above, and I think the disagreement is substantive rather than terminological.

The distinction being drawn does not survive when you look at the published data for this specific question. I would be glad to be shown wrong on this, because the version I am arguing against is more convenient.

6 likes 17mo

s.silvaTL2 Moderator16 Apr 2025#6

Limitations of datasets: all community-collected data has limitations. The population is self-selected (people in this community are not representative of all people using these compounds). Reporting bias is real (remarkable outcomes get reported; mundane outcomes do not).

16 likes 15mo

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