A blog on statistical practice, programming, history, philosophy, and data science.


Conceptualizing the readmission risk pool

Readmissions
Healthcare

Thinking in terms of what is actionable

Jan 5, 2026
Alex Zajichek

Investigating a Hospital-Specific Report (HSR)

Software Development
Healthcare
Readmissions

Analysis strategies to gain insight into HRRP program results

Dec 26, 2025
Alex Zajichek

Introducing the {readmit} R package

Software Development
Healthcare
Readmissions

Tools for analyzing hospital readmissions data

Dec 19, 2025
Alex Zajichek

Trying AI-assisted development in the Positron IDE

AI
Shiny
Web Applications

The ultimate setup for using an AI-companion for data science development.

Oct 29, 2025
Alex Zajichek

The question is not if, but how much

Philosophy
Statistical Significance
Decision Making

We focus on a binary that doesn’t exist.

Sep 26, 2025
Alex Zajichek

Building a custom LLM-powered Shiny app for hospital readmissions with {querychat}

AI
Shiny
Web Applications

How we can use natural language to interact with and manipulate app content.

May 23, 2025
Alex Zajichek

Making an AI statistical consultant

AI
Shiny
Web Applications

Exploring some new R packages for AI.

May 13, 2025
Alex Zajichek

What decision are we trying to make, anyway?

Philosophy
Statistical Significance
Decision Making

The crux of the statistical significance issue.

Apr 23, 2025
Alex Zajichek

How to reconcile the regression equation from spline terms

Regression

Using the {rms::rcs} function

Nov 25, 2024
Alex Zajichek

Can you have a model without data?

Bayesian Statistics

Yes, by being a Bayesian.

Oct 29, 2024
Alex Zajichek

You should have a data science blog

Deployment
Learning
Software Development

Easy and free are only a couple benefits.

Sep 25, 2024
Alex Zajichek

Low cost ways to build and deploy analytical web apps

Web applications
Deployment

An overview of some server options

Aug 20, 2024
Alex Zajichek

A prediction system for managing the hospital readmission risk pool

Healthcare
Modeling
Prediction
Readmissions

Proposed framework

Jul 26, 2024
Alex Zajichek

How do you assess the proportional-odds assumption? Directly.

Regression

A simple visual check.

Jul 19, 2024
Alex Zajichek

A simple example why statistical significance is insufficient for action

Statistical Significance
Decision Making

It ignores the basic question: “How much?”

Jun 19, 2024
Alex Zajichek

5 ways to help ensure success of a statistical project

Project Management

How can we increase the likelihood that things will go as expected?

May 16, 2024
Alex Zajichek

Quantum entanglement from a statistician’s perspective

Quantum
Probability

I’m a total beginner, but this stuff is interesting

Feb 16, 2024
Alex Zajichek

On the Creation of Classical Statistics

History
Philosophy

Fisher was in fact, a genius

Feb 10, 2024
Alex Zajichek

Statistical significance is…insignificant

History
Philosophy
Research
Statistical Significance

“A cheap way to get marketable results” -William Kruskal

Dec 22, 2023
Alex Zajichek

The overlap weight in survival analysis

Causal Inference
Survival Analysis
Propensity Scores
Weighting

A simulation review

Oct 2, 2023
Alex Zajichek

Removing higher-order aggregation text in {reactable}

Tables
Javascript
Often when I’m building a reactable I have potentially many aggregation levels but only want to display data in a lower subset of those. Here is a quick way to eliminate…
Jun 29, 2023
Alex Zajichek

Nesting with {tidyr}

Data Wrangling
I really love the elegance of the nest functionality with the tidyr package. It really allows you to abstract the meaning of a data frame to not just contain rectangular…
Feb 2, 2023
Alex Zajichek

Some Takeaways from Effective Data Storytelling

Communication
I’ve been reading through the book Effective Data Storytelling: How to drive change with data, narrative, and visuals by Brent Dykes and just wanted to document some…
Jan 14, 2023
Alex Zajichek

The Evasive Spline

Estimation
Modeling

Basis Functions & Splines

Jan 13, 2023
Alex Zajichek

(Re)deriving a Bernoulli MLE

Estimation

Trying to remember calculus

Jan 12, 2023
Alex Zajichek

Statistical Rethinking 2023 Class Notes

Bayesian Statistics
Causal Inference
This document is intended to be a repository for my (raw, unedited) notes, interpretations, examples, and summaries from the Statistical Rethinking 2023 course (which…
Jan 1, 2023
Alex Zajichek

A couple useful JavaScript aggregation and formatting functions for {reactable}

Healthcare
Tables
Javascript

Embedding tables into your analytical HTML document

Jul 31, 2022
Alex Zajichek

Building a filterable map with {leaflet} and {crosstalk} for hospital readmissions

Healthcare
Maps
Javascript

For runtime-free analytical content delivery

Jun 18, 2022
Alex Zajichek

Exploring COM Poisson regression

Regression

A method for underdispersed count data

Dec 28, 2021
Alex Zajichek

A look at collider bias

Causal Inference
There has been a lot of buzz around “causal inference” and given how fundamental the name seems to statistics, I picked up The Book of Why: The New Science of Cause and Effect…
Jul 15, 2021
Alex Zajichek
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