Welcome to our conference badge game! This year each participant’s badge contains one of three symbols, which are based on their first and last names, and roles:
decoder
autoencoder
encoder
f(first_name, last_name, role) ∈ {decoder, autoencoder, encoder}
As in classic machine learning problems, your task is to collect data and discover the unknown mapping function. The first five participants who correctly predict all the labels for the test set and give a short description of the function will receive special prizes.
Curious what the game looked like before? See last year’s badge game together with its solution.
The rules are simple – collect as much data as possible and discover the mapping function to accurately predict the labels of the test set. Participants who will succeed with their predictions have a chance to win prizes. If none of the participants solve the puzzle by the end of the conference, the prizes will be drawn among all participants who get the highest number of correct predictions on the test set. You can network with other participants to collect their names and associated labels and visit sponsor booths to collect extra data points that will help you discover the mapping function.
The assigned labels are printed on the back of the badges, so you can ask other participants to show them.
Don’t worry if you can’t find the pattern right away – we will provide hints to guide you in solving the mapping function. But remember, the faster you solve the puzzle, the higher are your chances of winning.

Submit your predictions for the test set names by filling out the form – you can make multiple submissions (under a reasonable limit). Along with your predictions, include a short description of the function you discovered.
Submissions are closed.
The label is a vote of three features. Each feature votes +1 (encoder), −1 (decoder) or 0, and the votes are summed: a positive score gives encoder, a negative one gives decoder, and zero gives autoencoder.
Before anything else, the name is cleaned: diacritics are dropped (e.g. ł → l, ó → o), case is ignored and only the letters A–Z are kept.
For example, Yoshua Bengio (invited speaker): the role votes −1; YOSHUA has an average width of 14.83 and BENGIO 8.67, so the name narrows and votes +1; it has 5 left-hand and 7 right-hand letters, so the keyboard votes −1. The score is −1, so the label is decoder. Michael Bronstein (participant): the role votes +1; MICHAEL (7.29) widens to BRONSTEIN (12.89), so −1; 8 left-hand and 8 right-hand letters give 0. The score is 0, so the label is autoencoder.
| Name | Role | Label |
|---|---|---|
| Yoshua Bengio | invited speaker | decoder |
| Michael Bronstein | participant | autoencoder |
| Rich Caruana | invited speaker | encoder |
| Kyle Cranmer | invited speaker | encoder |
| Richard Hamming | participant | autoencoder |
| Łukasz Kaiser | invited speaker | encoder |
| Diederik Kingma | participant | autoencoder |
| Daphne Koller | invited speaker | decoder |
| Marta Kwiatkowska | invited speaker | decoder |
| Tomas Mikolov | participant | decoder |
| Niki Parmar | participant | decoder |
| Marian Rejewski | participant | encoder |
| Jerzy Różycki | participant | encoder |
| Jakob Uszkoreit | participant | autoencoder |
| Laurens van der Maaten | participant | encoder |
| Henryk Zygalski | participant | decoder |