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Adrian Olszewski @adrianolsz.bsky.social · 22/03/2025

Two examples of using logistic regression (&friends) for model-based testing hypotheses & estimation. I show the equivalence of Wald's "z" statistic for two proportions with pooled and unpooled variance vs logistic r. + AME / Rao. 1: medium.com/@r.clin.res/... 2: medium.com/@r.clin.res/... #stats

medium.com

Testing hypotheses about proportions (%) through the logistic regression (and friends) — part II

In my previous article titled “Is logistic regression a regression? It has been a regression since its birth — and is used this way every…

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Adrian Olszewski @adrianolsz.bsky.social · 01/03/2025

#stats Sometimes, at work, I feel like I'm the only person who cares about the success of the study...

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Adrian Olszewski @adrianolsz.bsky.social · 29/01/2025

That's how it sometimes looks like when #stats (here: in clinical #biostatistics) meets #machinelearning with a little 𝘪𝘮𝘱𝘦𝘥𝘢𝘯𝘤𝘦 𝘮𝘪𝘴𝘮𝘢𝘵𝘤𝘩 on some topic common in both places 🙃 (happened to me twice so far).

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Adrian Olszewski @adrianolsz.bsky.social · 30/12/2024

- Adrian, logistic regression is NOT a regression, it's a classifier! - O'rly? I've never used it for classification while using it daily at work to test hypotheses and explore treatment effects😬 I bet #stats guys who invented it didn't know this... revelation too 🙄 #ml #machinelearning #datascience

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Adrian Olszewski @adrianolsz.bsky.social · 18/12/2024

The moment, when you feel the nonsense of 𝙋𝙊𝙎𝙏-𝙃𝙊𝘾 𝙋𝙊𝙒𝙀𝙍 and yet the same concept is essential for👉 𝙙𝙚𝙨𝙞𝙜𝙣𝙞𝙣𝙜 𝙨𝙩𝙪𝙙𝙞𝙚𝙨, namely calculating the sample size: 1) to determine the safety range for dropouts 2) when there's no closed-form formula (like for the Fisher exact test) #statistics #stats #rstats

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Adrian Olszewski @adrianolsz.bsky.social · 14/12/2024

#statistics #stats Reading QQ plots is not easy at first. I can relate! But don't give up just because it's hard. Everything is hard until you know it and suddenly it becomes your daily tool. Practising and mastering QQ plots (and CDF, BTW) isn't a waste of time! Below I show a few examples.

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Adrian Olszewski @adrianolsz.bsky.social · 10/12/2024

#rstats #ggplot2 I must say I really *like* the gghalves package and the idea of the #raincloud plots 🥰 In my toolkit (#clinicaltrials) for 8 years. Below - various examples (from toy experiments and real reports). Luckily to me, my collaborators love them too (and even demand!).

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Adrian Olszewski @adrianolsz.bsky.social · 10/12/2024

Anscombe's quartet, Datasaurus dozen... I wanted to make my own set with same (basic) descriptive summaries. Let me introduce the Olszewski's quartet 😎 Yeah, I could easily make both kurtosis and skewness equal too, but I like the asymmetry of the nose and eyes 😂 github.com/adrianolszew... #rstats

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Adrian Olszewski @adrianolsz.bsky.social · 05/12/2024

For ~15yrs on ~weekly basis at work you've been using the logistic regression for exploring main & simple effects + interactions & testing hypotheses, and suddenly a #ML guru tells you that "nope, logistic regression is not a regression, it gives 0/1😎". And pufff! - you disappear like in Disney's💥🤦‍♂️

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Adrian Olszewski @adrianolsz.bsky.social · 04/12/2024

Worth remembering: rank-based tests like Kruskal-Wallis, Mann-Whitney (-Wilcoxon), ATS/WTS - do NOT compare medians unless IID holds (=same shape & dispersion). Otherwise, stochastic superiority is assessed. Use quantile regression (+ Wald's testing) or Brown-Mood instead. #statistics #datascience

Three boxplots with equal medians yet Kruskal-Wallis and individual pairwise Mann-Whitney comparisons report very low p-values. They do not compare medians unless the sample data are IID.

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Adrian Olszewski @adrianolsz.bsky.social · 04/12/2024

My "hello world" post 🫡 - a few slides about a viewpoint called 𝙌𝙪𝙚𝙩𝙞𝙡𝙞𝙨𝙢𝙪𝙨 (after Adolphe Quetelet), which initiated the "cult" of the normal distribution I've been observing for years. www.slideshare.net/slideshow/ch... Or a longer text: www.2kmm.pl/blog/On-the-... #statistics #ml #datascience

slideshare.net

Challenging the cult of the normal distribution in science

Challenging the cult of the normal distribution in science - Download as a PDF or view online for free

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Adrian Olszewski @adrianolsz.bsky.social · 04/12/2024

If you're interested in #RStats in #clinicaltrials, check my two older (2020-2) presentations from the #rinpharma conference on the numerical validation of R. I work in a 100%R CRO, my daily challenges might be interesting. www.researchgate.net/publication/... and www.slideshare.net/AdrianOlszew...

researchgate.net

(PDF) Numerical validation as a critical aspect in bringing R to the Clinical Research

PDF | Validation of the R statistical package has become a hot topic since 2015, when the FDA issued the Statistical Software Clarifying Statement,... | Find, read and cite all the research you need o...

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