December 2026 · Advent ML
Advent ML
Twelve tasks for twelve days: from 1 to 12 December 2026 a new door opens every day. Each task is a small exercise on a well-known dataset, with a result you compute yourself and enter to be checked.
What it is
- Twelve machine learning tasks, one a day: a decision tree on Titanic, k-means on irises, PCA on wines, a decision threshold in diagnostics, Simpson’s paradox and more.
- Each task gives the exact settings (split, seed, parameters), so the result can be reproduced in Python. You need scikit-learn, pandas and seaborn.
- The answer is a number. It is checked with the stated tolerance, so a small difference between library versions will not void a good result.
Dates
- Door 1 opens on 1 December 2026 at midnight Warsaw time, the next ones at the same time every day; the last one, door 12, on 12 December.
- Worked solutions with code are available once you solve a task, and for everyone from 13 December 2026.
- The tasks stay on the page after the Advent ends.
Download the calendar file (.ics) A .ics file with twelve all-day events, 1–12 December 2026. It opens in Google Calendar, Outlook and Apple Calendar.
Twelve doors
Dates follow Warsaw time. Closed doors show only a title.
- 1Titanic: how far does a depth-2 tree get?Door 1 · · Titanic
- 2Iris: can k-means find the species?Door 2 · · Iris
- 3Penguins: how much mass does the flipper explain, and how much the species?Door 3 · · Palmer Penguins
- 4Wine: two dimensions instead of thirteenDoor 4 · · Wine
- 5Breast cancer: the decision threshold and false alarmsDoor 5 · · Breast Cancer Wisconsin
- 6Digits: how many mistakes will a random forest make?Door 6 · · Digits
- 7Diabetes: which features will Lasso zero out?Door 7 · · Diabetes
- 8Anscombe: how far is the worst point from the line?Door 8 · · Anscombe
- 9Berkeley: Simpson’s paradox in numbersDoor 9 · · Berkeley 1973
- 10Wine: feature scaling in kNNDoor 10 · · Wine
- 11Titanic: how much better were the odds for women?Door 11 · · Titanic
- 12Digits: PCA before kNNDoor 12 · · Digits
The tasks open in a browser with JavaScript enabled.
How it works
- Before its date a door shows only a title. The task text is loaded only on the day it opens.
- Each task has two or three hints, uncovered one at a time.
- Progress and the day streak are stored in this browser. No account is needed and there is no global ranking.
- The result to share is coloured squares and the number of solved days, with no task text and no answers.
- The tasks need JavaScript; without it you see only this announcement.
Groups
Coming soon: groups for student societies and teams, that is private score tables with no global ranking. For now everyone practises alone.
Reference datasets
The tasks run on datasets that the Atlas describes on their own pages. See the datasets.