Learn with Phoebe Β· Data Science

Learn The Two Cultures with Phoebe

In 2001 Leo Breiman told statisticians there were two ways to learn from data: assume an equation generated it and read the answer off the equation, or leave nature's box shut and judge a model only by how well it predicts rows it has never seen. Four eminent statisticians replied in the same issue, and they did not agree. Twenty-five years on, every argument about explainable versus accurate, statistics versus machine learning, or "a model the regulator can read" is a descendant of that exchange. Six sessions read it at source, together with George Box on useful models, John Tukey on exploring before you confirm, and David Donoho's fifty years of data science, then put both cultures on the same 569 real biopsies in your browser and count.

6sessions
5papers read at source
569real biopsies
171held out, graded once
45min per session

The six sessions πŸ“œ Β· from one black box to a choice you can defend

Two colours run through every figure and widget, so each culture always looks the same.

The data modelling culture

Assume a stochastic model generated the data, estimate its parameters, read nature's mechanism off the equation. Validated by goodness-of-fit: a yes or no.

The algorithmic culture

Treat the inside of the box as unknown, find a function that predicts y from x, and trust it only as far as its accuracy on unseen rows: a number.

πŸ“¦ Session 1 Β· advanced

Two ways to ask the data

Breiman's black box, the two cultures in his own words, the consulting projects that made him one of the 2 percent, and the hepatitis example where an unchecked model names the wrong variables. Build-along: both cultures on the same biopsies.

β–Ά Start here
🧭 Session 2 · advanced

All models are wrong, some are useful

Where Box actually wrote it: the idea twice in 1976, the sentence as a 1979 section heading. What "useful" means as three checks you can run, and a regression that is 99.4 percent right with coefficients that point the wrong way.

tigers, not mice
πŸ”Ž Session 3 Β· advanced

Explore first, confirm once

Tukey's 1962 case that data analysis is a science, exploratory work as detective work, and the discipline that keeps a confirmation honest: rows nobody touched until the end.

the untouched set
βš–οΈ Session 4 Β· bench night

The two-cultures bench

A logistic regression and a random forest fitted in your browser on 569 real biopsies. Held-out accuracy and explanation size side by side, the base rate, a break button, and a peek switch that lies.

β˜… the bench
πŸ—ΊοΈ Session 5 Β· advanced

Fifty years of data science

Donoho's 2017 history from Tukey to today, the common task framework he calls the secret sauce of machine learning, and the six divisions of greater data science, where both cultures share one division.

the secret sauce
🀝 Session 6 · advanced

Which culture is this question?

Cox, Efron, Hoadley and Parzen in their own words, Breiman's rejoinder, and a way to choose a culture per problem that keeps their disagreement intact rather than pretending it was settled.

πŸ”’ final passport stamp
advanced bench night

Your passport 🎫

Clear all three quiz questions in a session and it gets stamped. Six stamps means you can classify any model by culture, say what its validation does and does not license, keep a confirmation honest, and argue both sides of the 2001 exchange. Stamps live in this browser only.

What this is not, so you land in the right place 🧭

If your question isGo here instead
Why should I believe this model's test score, and what does a benchmark license?ML Epistemology β†—
Many models fit equally well and tell different stories. Which one do I trust?ML Epistemology, leader session 2 β†—
Frequentist or Bayesian, and how do I choose a prior?Bayesian, leader session 5 β†—
How does a random forest actually work?Ensemble Methods, session 2 β†—
How do I read the numbers my team brings me?Data Literacy β†—
How do I turn a business worry into a question data can answer?Data Thinking β†—
Where did the split between statistics and machine learning come from, what did each side actually claim, and how do I choose for a given problem?you are in the right place

Choose your path πŸ—ΊοΈ

Three doors into the same conviction: a model is a claim, and the way it is checked decides what it lets you say.

πŸ§‘β€πŸ’Ό I sign off on models, I do not build them 1β†’ 2β†’ 6 the two cultures, what useful means, and which one your question needs
πŸ› οΈ I build models and want the history behind my habits 1β†’ 3β†’ 4β†’ 5 the split, the untouched test set, the bench, and the framework that made it a field
πŸ“œ The whole argument 1β†’ 2β†’ 3β†’ 4β†’ 5β†’ 6 four authors, one bench, and a choice you can defend

What is honest here 🧾

The pages quote the papers themselves. Where a famous line could not be read in its original, the page says so and labels it reported.

ClaimStatus
Breiman 2001, and the comments by Cox, Efron, Hoadley and Parzen with Breiman's rejoinderRead at source, Statistical Science 16(3), all 33 pages
Box: "Since all models are wrong" (1976) and "All models are wrong but some are useful" (1979)Read at source, JASA 71(356) and Robustness in Statistics, Academic Press. The "essentially" version of 1987 is reported
Tukey 1962, The Future of Data AnalysisRead at source, all 67 pages. The 1977 book and the 1980 paper on exploratory and confirmatory analysis are reported
Donoho 2017, 50 Years of Data ScienceRead at source, Journal of Computational and Graphical Statistics 26(4)
Every number on the benchReally computed in your browser from the 569 real rows of UCI Breast Cancer Wisconsin (Diagnostic), and reproduced exactly by an independent Python run
"Culture X wins"Not claimed. One dataset, nearly linearly separable; the pages teach the disagreement, not a verdict

The knowledge map 🧠

The whole argument at a glance - hover a session to spotlight its concepts, click any node to jump in.