Allen Downey
@allendowney.bsky.social
Former professor at Olin College, principal data scientist at PyMC Labs, author of Think Python, and Probably Overthinking It -- blog and book -- and stark raving Bayesian.
“I’m way closer to LeBron James than you are to me.”
-- Brian Scalabrine
He's probably right, because in a lognormal distribution of ability, it's levels to this …
www.allendowney.com/blog/2025/11...
-- Brian Scalabrine
He's probably right, because in a lognormal distribution of ability, it's levels to this …
www.allendowney.com/blog/2025/11...
It's Levels - Probably Overthinking It
A recent Reddit post asks “Amateur athletes of Reddit: what’s your ‘There’s levels to this shit’ experience from your sport?” Responses included: We have some good runners who can win local races … An...
www.allendowney.com
November 4, 2025 at 3:52 PM
“I’m way closer to LeBron James than you are to me.”
-- Brian Scalabrine
He's probably right, because in a lognormal distribution of ability, it's levels to this …
www.allendowney.com/blog/2025/11...
-- Brian Scalabrine
He's probably right, because in a lognormal distribution of ability, it's levels to this …
www.allendowney.com/blog/2025/11...
Reposted by Allen Downey
The #Scicloj group is initiating a new study group:
#DSP in #Clojure.
We will follow @allendowney.bsky.social's #ThinkDSP book and practice it in Clojure.
clojureverse.org/t/clojure-ds...
#DSP in #Clojure.
We will follow @allendowney.bsky.social's #ThinkDSP book and practice it in Clojure.
clojureverse.org/t/clojure-ds...
Clojure DSP meeting 2025-11-02
Once in a while, a few of the Scicloj freinds will meet to learn about signal processing, following the Think DSP book by Allen B. Downey, and implementing things in Clojure. Our notes will be publish...
clojureverse.org
November 2, 2025 at 10:22 AM
The #Scicloj group is initiating a new study group:
#DSP in #Clojure.
We will follow @allendowney.bsky.social's #ThinkDSP book and practice it in Clojure.
clojureverse.org/t/clojure-ds...
#DSP in #Clojure.
We will follow @allendowney.bsky.social's #ThinkDSP book and practice it in Clojure.
clojureverse.org/t/clojure-ds...
The newest chapter of Think Linear Algebra is up now!
It is about least squares regression, QR decomposition, and orthogonality:
allendowney.github.io/ThinkLinearA...
It is about least squares regression, QR decomposition, and orthogonality:
allendowney.github.io/ThinkLinearA...
October 29, 2025 at 2:30 PM
The newest chapter of Think Linear Algebra is up now!
It is about least squares regression, QR decomposition, and orthogonality:
allendowney.github.io/ThinkLinearA...
It is about least squares regression, QR decomposition, and orthogonality:
allendowney.github.io/ThinkLinearA...
Five-year survival rates might be the most misleading statistics in medicine.
Even smart people can make incorrect inferences. Here are the top four:
1. If a patient is diagnosed early, it is tempting to think the probability is 91% that they will survive five years after diagnosis.
Even smart people can make incorrect inferences. Here are the top four:
1. If a patient is diagnosed early, it is tempting to think the probability is 91% that they will survive five years after diagnosis.
October 27, 2025 at 1:58 PM
Five-year survival rates might be the most misleading statistics in medicine.
Even smart people can make incorrect inferences. Here are the top four:
1. If a patient is diagnosed early, it is tempting to think the probability is 91% that they will survive five years after diagnosis.
Even smart people can make incorrect inferences. Here are the top four:
1. If a patient is diagnosed early, it is tempting to think the probability is 91% that they will survive five years after diagnosis.
The original sin of the engineering curriculum is the Foundation Fallacy:
The assumption that math (especially calculus) and science (especially physics) are (1) the foundations of engineering, and therefore (2) the prerequisites of engineering education.
www.allendowney.com/blog/2025/10...
The assumption that math (especially calculus) and science (especially physics) are (1) the foundations of engineering, and therefore (2) the prerequisites of engineering education.
www.allendowney.com/blog/2025/10...
The Foundation Fallacy - Probably Overthinking It
At Olin College recently, I met with a group from the Kyiv School of Economics who are creating a new engineering program. I am very impressed with the work they are doing, and their persistence despi...
www.allendowney.com
October 22, 2025 at 6:52 PM
The original sin of the engineering curriculum is the Foundation Fallacy:
The assumption that math (especially calculus) and science (especially physics) are (1) the foundations of engineering, and therefore (2) the prerequisites of engineering education.
www.allendowney.com/blog/2025/10...
The assumption that math (especially calculus) and science (especially physics) are (1) the foundations of engineering, and therefore (2) the prerequisites of engineering education.
www.allendowney.com/blog/2025/10...
I just posted a new chapter of Think Linear Algebra.
It's about projection, rejection, rotation, and pool!
allendowney.github.io/ThinkLinearA...
It's about projection, rejection, rotation, and pool!
allendowney.github.io/ThinkLinearA...
October 19, 2025 at 5:54 PM
I just posted a new chapter of Think Linear Algebra.
It's about projection, rejection, rotation, and pool!
allendowney.github.io/ThinkLinearA...
It's about projection, rejection, rotation, and pool!
allendowney.github.io/ThinkLinearA...
I love a good Simpson's paradox. Sadly, this is not one of them
www.allendowney.com/blog/2025/10...
In fact, I think the whole paper is nonsense.
Published in Nature, too.
www.allendowney.com/blog/2025/10...
In fact, I think the whole paper is nonsense.
Published in Nature, too.
Simpson's What? - Probably Overthinking It
I like Simpson’s paradox so much I wrote three chapters about it in Probably Overthinking It. In fact, I like it so much I have a Google alert that notifies me when someone publishes a new example (or...
www.allendowney.com
October 16, 2025 at 8:05 PM
I love a good Simpson's paradox. Sadly, this is not one of them
www.allendowney.com/blog/2025/10...
In fact, I think the whole paper is nonsense.
Published in Nature, too.
www.allendowney.com/blog/2025/10...
In fact, I think the whole paper is nonsense.
Published in Nature, too.
Sadly, my primary team (the Red Sox) and emergency backup team (the Padres) were both knocked out of the playoffs yesterday.
Now I am left to cheer for my team of last resort (the Notyankees).
Now I am left to cheer for my team of last resort (the Notyankees).
October 3, 2025 at 5:40 PM
Sadly, my primary team (the Red Sox) and emergency backup team (the Padres) were both knocked out of the playoffs yesterday.
Now I am left to cheer for my team of last resort (the Notyankees).
Now I am left to cheer for my team of last resort (the Notyankees).
Sometimes we can use Bayesian methods to infer the effect of selection bias and produce an unbiased estimate.
Here's an example that uses PyMC to solve a classic probability puzzle (the image shows what I think is the original version).
www.allendowney.com/blog/2025/09...
Here's an example that uses PyMC to solve a classic probability puzzle (the image shows what I think is the original version).
www.allendowney.com/blog/2025/09...
September 26, 2025 at 1:43 PM
Sometimes we can use Bayesian methods to infer the effect of selection bias and produce an unbiased estimate.
Here's an example that uses PyMC to solve a classic probability puzzle (the image shows what I think is the original version).
www.allendowney.com/blog/2025/09...
Here's an example that uses PyMC to solve a classic probability puzzle (the image shows what I think is the original version).
www.allendowney.com/blog/2025/09...
Reposted by Allen Downey
At this point I'm just barely making enough $ on this cohort to cover the platform fees.
It's going to run anyway but I'd really love to have a few more people signed up.
Use the code SIXTY for 60% off at registration.
It's going to run anyway but I'd really love to have a few more people signed up.
Use the code SIXTY for 60% off at registration.
The autumn evening cohort for Binoculars to Binomials starts Thursday.
Which means you have a little over 48 hours to jump on board!
Get to know your local birds, learn some fun approaches to data viz, and... completely rewire your 🧠?
jerthorp.me/learning
Which means you have a little over 48 hours to jump on board!
Get to know your local birds, learn some fun approaches to data viz, and... completely rewire your 🧠?
jerthorp.me/learning
September 24, 2025 at 8:02 PM
At this point I'm just barely making enough $ on this cohort to cover the platform fees.
It's going to run anyway but I'd really love to have a few more people signed up.
Use the code SIXTY for 60% off at registration.
It's going to run anyway but I'd really love to have a few more people signed up.
Use the code SIXTY for 60% off at registration.
I have published five new chapters of Think Linear Algebra!
Read about the project here
allendowney.com/blog/2025/09...
Or jump straight to the book
allendowney.github.io/ThinkLinearA...
And now… Asteroids!
Read about the project here
allendowney.com/blog/2025/09...
Or jump straight to the book
allendowney.github.io/ThinkLinearA...
And now… Asteroids!
September 22, 2025 at 2:41 PM
I have published five new chapters of Think Linear Algebra!
Read about the project here
allendowney.com/blog/2025/09...
Or jump straight to the book
allendowney.github.io/ThinkLinearA...
And now… Asteroids!
Read about the project here
allendowney.com/blog/2025/09...
Or jump straight to the book
allendowney.github.io/ThinkLinearA...
And now… Asteroids!
On September 3 I'm giving a talk for the Boston Python User Group, called "A Future of Data Science"
www.meetup.com/bostonpython...
This is a talk from posit::conf last year, updated with new data and the experience of an interesting year.
www.meetup.com/bostonpython...
This is a talk from posit::conf last year, updated with new data and the experience of an interesting year.
Presentation Night: A future of data science (Allen Downey), Wed, Sep 3, 2025, 6:00 PM | Meetup
**A future of data science**
*Allen Downey*
In the hype cycle of data science, I suggest that the "peak of inflated expectations" was in 2012, the "trough of disillusionme
www.meetup.com
August 19, 2025 at 7:42 PM
On September 3 I'm giving a talk for the Boston Python User Group, called "A Future of Data Science"
www.meetup.com/bostonpython...
This is a talk from posit::conf last year, updated with new data and the experience of an interesting year.
www.meetup.com/bostonpython...
This is a talk from posit::conf last year, updated with new data and the experience of an interesting year.
Between 2021 and 2024, marijuana was legalized in eight states totaling 18% of the US population. During this time, adult use increased and youth use was unchanged.
Data from NSDUH 2024.
Data from NSDUH 2024.
August 13, 2025 at 5:16 PM
Between 2021 and 2024, marijuana was legalized in eight states totaling 18% of the US population. During this time, adult use increased and youth use was unchanged.
Data from NSDUH 2024.
Data from NSDUH 2024.
As a graduate of an all-boys high school, I am very interested to see the results...
Two decades ago, the U.S. loosened Title IX to allow single-sex schools.
What does the research tell us about all-boys schools? Ben Smith outlines the highlights:
What does the research tell us about all-boys schools? Ben Smith outlines the highlights:
All-boys schools: What do we know?
All-boys schooling is back in focus as boys fall behind. Explore trends, research, and policies on single-sex education.
aibm.org
July 24, 2025 at 10:04 PM
As a graduate of an all-boys high school, I am very interested to see the results...
For anyone who likes LLMs and daytime game shows.
We made LLMs play The Price Is Right — with real-world CPG prices.
50 models. One goal: bid as close as possible without going over.
🤖 Some nailed it
💸 Some flopped hard
What does this say about LLMs as synthetic consumers?
Full story 👇
dub.link/llms-price-r...
50 models. One goal: bid as close as possible without going over.
🤖 Some nailed it
💸 Some flopped hard
What does this say about LLMs as synthetic consumers?
Full story 👇
dub.link/llms-price-r...
Can LLMs play The Price is Right?
Synthetic consumers—LLMs simulating human survey participants—are becoming a powerful tool for marketing and behavioral research. They promise faster iteration, lower costs, and broader flexibility th...
dub.link
July 24, 2025 at 2:05 PM
For anyone who likes LLMs and daytime game shows.
Some news articles suggest young men are conservative Republicans with sexist attitudes.
But big picture, young men's views are pretty much on trend.
Here's the data: allendowney.substack.com/p/are-young-...
But big picture, young men's views are pretty much on trend.
Here's the data: allendowney.substack.com/p/are-young-...
Are Young Men Veering Right? Not really.
On most issues, gender gaps are small and not much different among young and older people
allendowney.substack.com
July 23, 2025 at 2:15 PM
Some news articles suggest young men are conservative Republicans with sexist attitudes.
But big picture, young men's views are pretty much on trend.
Here's the data: allendowney.substack.com/p/are-young-...
But big picture, young men's views are pretty much on trend.
Here's the data: allendowney.substack.com/p/are-young-...
We're kicking off this new workshop on August 5.
If you can’t explain your model, can you really trust it?
🎥 Hear from Evan Wimpey on how our Applied Bayesian Modeling Workshop teaches you to build transparent, business-ready models with PyMC.
Seats are limited → dub.link/bayes-modeling
#PyMC #MCMC #DataScience
🎥 Hear from Evan Wimpey on how our Applied Bayesian Modeling Workshop teaches you to build transparent, business-ready models with PyMC.
Seats are limited → dub.link/bayes-modeling
#PyMC #MCMC #DataScience
July 22, 2025 at 2:10 PM
We're kicking off this new workshop on August 5.
Reposted by Allen Downey
Everyone can do ML. Few can do Bayesian modeling.
Set yourself apart with skills that drive deeper insight + better decisions.
Join the next Applied Bayesian Modeling Workshop by PyMC Labs. Hands-on. Practical. Real-world.
📅 Limited seats → dub.link/bayes-workshop
#PyMC
Set yourself apart with skills that drive deeper insight + better decisions.
Join the next Applied Bayesian Modeling Workshop by PyMC Labs. Hands-on. Practical. Real-world.
📅 Limited seats → dub.link/bayes-workshop
#PyMC
July 14, 2025 at 12:50 PM
Everyone can do ML. Few can do Bayesian modeling.
Set yourself apart with skills that drive deeper insight + better decisions.
Join the next Applied Bayesian Modeling Workshop by PyMC Labs. Hands-on. Practical. Real-world.
📅 Limited seats → dub.link/bayes-workshop
#PyMC
Set yourself apart with skills that drive deeper insight + better decisions.
Join the next Applied Bayesian Modeling Workshop by PyMC Labs. Hands-on. Practical. Real-world.
📅 Limited seats → dub.link/bayes-workshop
#PyMC
ChatGPT and I think that "AI tools are shifting the boundary of what’s viable, and that’s likely to increase the net demand for software development, not decrease it."
More Viable Projects = More Things to Build
chatgpt.com/share/686c2e...
More Viable Projects = More Things to Build
chatgpt.com/share/686c2e...
July 7, 2025 at 8:29 PM
ChatGPT and I think that "AI tools are shifting the boundary of what’s viable, and that’s likely to increase the net demand for software development, not decrease it."
More Viable Projects = More Things to Build
chatgpt.com/share/686c2e...
More Viable Projects = More Things to Build
chatgpt.com/share/686c2e...
Starting August 5, PyMC Labs is running a new workshop on Bayesian modeling in PyMC -- and I'm one of the instructors.
If you want to get started with Bayesian stats, this is your chance! See below for details.
If you want to get started with Bayesian stats, this is your chance! See below for details.
🚨 We’re opening our private Bayesian modeling workshops to the public — for the first time
After this course, you won’t just build better models.
You’ll know how to explain them — to technical and non-technical stakeholders alike
🎓 Led by top PyMC experts.
📎 Register here: dub.link/68uMjpp
After this course, you won’t just build better models.
You’ll know how to explain them — to technical and non-technical stakeholders alike
🎓 Led by top PyMC experts.
📎 Register here: dub.link/68uMjpp
July 7, 2025 at 7:09 PM
Starting August 5, PyMC Labs is running a new workshop on Bayesian modeling in PyMC -- and I'm one of the instructors.
If you want to get started with Bayesian stats, this is your chance! See below for details.
If you want to get started with Bayesian stats, this is your chance! See below for details.
I love this -- possibly best ever.
![5-panel comic. (1) [teacher with long hair next to whiteboard] TEACHER: I’m supposed to give you the tools to do good science. (2) [teacher addressing students] But what *are* those tools? Methodology is hard and there are so many ways to get incorrect results. What is the magic ingredient that makes for good science? (3) TEACHER: To figure it out, I ran a regression with all the factors people say are important: [embedded list in sub-panel, cut off at end] Outcome variable: correct scientific results. Predictors: collaboration; skepticism of others’ claims; questioning your own beliefs; trying to falsify hypotheses; checking citations; statistical rigor; blinded analysis; financial disclosure; open data (4) TEACHER: The regression says two ingredients are the most crucial: 1) genuine curiosity about the answer to a question, and 2) ammonium hydroxide. (5) STUDENT: Wait, why did *ammonia* score so high? How did it even get on the list? LONG HAIR: ...And now you’re doing good science!](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:cz73r7iyiqn26upot4jtjdhk/bafkreigzaphhj4mfgfrxddlvdmw47335gnwzqbfqvrnff5x4oovgpf36nq@jpeg)
June 12, 2025 at 8:56 PM
I love this -- possibly best ever.
At PyData Boston last night, I announced a new project: Think Linear Algebra!
This blog post explains the idea, including a sample chapter and a terrible AI-generated cover.
www.allendowney.com/blog/2025/05...
This blog post explains the idea, including a sample chapter and a terrible AI-generated cover.
www.allendowney.com/blog/2025/05...
Announcing Think Linear Algebra - Probably Overthinking It
I’ve been thinking about Think Linear Algebra for more than a decade, and recently I started working on it in earnest. If you want to get a sense of it, I’ve posted a draft chapter as a Jupyter notebo...
www.allendowney.com
May 29, 2025 at 3:03 PM
At PyData Boston last night, I announced a new project: Think Linear Algebra!
This blog post explains the idea, including a sample chapter and a terrible AI-generated cover.
www.allendowney.com/blog/2025/05...
This blog post explains the idea, including a sample chapter and a terrible AI-generated cover.
www.allendowney.com/blog/2025/05...
Reposted by Allen Downey
Can LLMs answer open-ended survey questions like real people? 🧠
@allendowney.bsky.social tested GPT-4, Claude & others on 2020 ANES data. Models matched the order of top concerns—but often cited issues (like inflation) that weren’t big then. Useful, but not time-aware.
👉 dub.link/synth-respon...
@allendowney.bsky.social tested GPT-4, Claude & others on 2020 ANES data. Models matched the order of top concerns—but often cited issues (like inflation) that weren’t big then. Useful, but not time-aware.
👉 dub.link/synth-respon...
Can Synthetic Consumers Answer Open-Ended Questions? - PyMC Labs
dub.link
May 14, 2025 at 4:31 PM
Can LLMs answer open-ended survey questions like real people? 🧠
@allendowney.bsky.social tested GPT-4, Claude & others on 2020 ANES data. Models matched the order of top concerns—but often cited issues (like inflation) that weren’t big then. Useful, but not time-aware.
👉 dub.link/synth-respon...
@allendowney.bsky.social tested GPT-4, Claude & others on 2020 ANES data. Models matched the order of top concerns—but often cited issues (like inflation) that weren’t big then. Useful, but not time-aware.
👉 dub.link/synth-respon...
My Think Stats hard copy has arrived!
Here's what's new in the third edition:
allendowney.github.io/ThinkStats/c...
Here's what's new in the third edition:
allendowney.github.io/ThinkStats/c...
April 28, 2025 at 12:38 PM
My Think Stats hard copy has arrived!
Here's what's new in the third edition:
allendowney.github.io/ThinkStats/c...
Here's what's new in the third edition:
allendowney.github.io/ThinkStats/c...
Time Series Analysis with StatsModels
Video from my PyData Global tutorial is up now:
www.youtube.com/watch?v=foMb...
Video from my PyData Global tutorial is up now:
www.youtube.com/watch?v=foMb...
Allen Downey - Time Series Analysis with StatsModels | PyData Global 2024
YouTube video by PyData
www.youtube.com
April 24, 2025 at 2:11 PM
Time Series Analysis with StatsModels
Video from my PyData Global tutorial is up now:
www.youtube.com/watch?v=foMb...
Video from my PyData Global tutorial is up now:
www.youtube.com/watch?v=foMb...