Theiss Bendixen

@theissbendixen.bsky.social

Data science & Bayes at Novo Nordisk | Author of "The Data Analyst's Guide to Cause and Effect" (https://theissbendixen.com/dag-book/) | Writing a book on Bayes in drug development | Board member, https://giveffektivt.dk/ www.theissbendixen.com

It took us three years to write this thing. But the good news is you can read it in three days! We cover fairly advanced methods -- counterfactuals, g-computation, inverse probability of treatment weighting, poststratification, missing data imputation, etc. -- without dense formal notation.

Nice! Similar phenomenon to assurance (or marginal/average power), where a prior is placed over the effect and power is integrated over it to account for uncertainty, rather than conditioning on a single point estimate. Assurance is also always lower than power in practice.

Dr Mircea Zloteanu 🌺🌞🍃@mzloteanu.bsky.social · 2mo ago

I made a #Shiny app about post hoc power and effect-size uncertainty. If you accept an observed effect, you also need to accept its uncertainty. The app shows how power wobbles when you consider the CI, not just the estimate. Embrace the #wobble #samplesize open.substack.com/pub/mzlotean...

Imagine a short book (~200 p.) introducing Bayesian statistics in the context of clinical trials and drug development. Scope would be introductory -- sort of "your first short course on Bayes". But practical enough to be applied out of the box. What would you like to see covered in such a text? 👇

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In the Fall I'll be teaching a new MA-level methods course entitled "Applied Statistical Evaluation of Development Projects". It will be 12 weeks, in R, and aimed around RCT evaluations. This is a draft outline. What am I missing? What seems redundant?

1. Course Introduction and Setup
 Course overview; installing RStudio; introduction to causal inference; ModernDive Chapters 1–2 for newcomers.
2. Data, Tidy Data, Wrangling, and Visualization
 Core R skills for importing, cleaning, reshaping, summarizing, and visualizing evaluation data.
3. Sampling, Uncertainty, and Inference 
Sampling variation, confidence intervals, hypothesis testing, and the logic of statistical uncertainty.
4. Difference in Means as Regression 
Equivalence between difference-in-means estimates and lm(y ~ treat); ATE as the treatment coefficient; control mean as the intercept; covariates for precision gains; simulations and re-analysis of Karlan–List charity data.
5. Interactions and Treatment Effect Heterogeneity 
Interaction terms, subgroup analysis, heterogeneous effects; simulations, Karlan–List charity data, and Thornton HIV data.
6. Standard Errors, Power, and Research Design 
Bias, variance, RMSE, clustering, power analysis, and how underpowered studies contribute to selection on significance and inflated estimates.
7. Noncompliance, Take-Up, and Instrumental Variables 
ITT, TOT, LATE, compliers etc, and randomized encouragement designs; Thornton HIV testing incentives; reading from The Effect Chapter 19 or Causal Inference: The Mixtape IV chapter.
8. Spillovers, Externalities, and Peer Effects
 How spillovers can bias experimental estimates; identifying, measuring, and interpreting spillover effects in development evaluations.
9. Pre-Analysis Plans, Measurement, and Cost-Effectiveness
 PAPs, outcome measurement, measurement error, index construction, and basic cost-effectiveness analysis.
10. Meta-Analysis and Evidence Aggregation 
Fixed-effect and random-effects meta-analysis; Bayesian meta-analysis using baggr; interpreting accumulated evidence across studies.
11. Case Study: Deworming Evidence I
 Critical re-analysis of the main deworming results; statistical interpretation; cost-effectiveness implications.

🚨 Blog post: When Using OLS Hurts 😩 I replicated a high-profile study on racial bias in tenure decisions and show the authors weakened their own findings by using OLS instead of ordered beta regression 🤯. Use ordered beta and live your best life 👍 #rstats www.robertkubinec.com/post/ord_bet...

When Using OLS Hurts – Homepage

People often use OLS for bounded continuous variables even though we know it isn’t the correct model. Ordered beta regression is a better model–but hard to predict when the results will change. For th...

robertkubinec.com

Imagine a short book (~200 p.) introducing Bayesian statistics in the context of clinical trials and drug development. Scope would be introductory -- sort of "your first short course on Bayes". But practical enough to be applied out of the box. What would you like to see covered in such a text? 👇

Bild

Yeah, Bayes is usually thought of as particularly useful with sparse data (because priors can do some of the work), but I think it's equally true that Bayes is useful when there's a lot of good data on e.g. a drug, because Bayes is very well-suited to exploit all that information in a principled way