The challenges are prediction, regression or classification problems, using real data provided by companies or research laboratories. They cover a wide spectrum of applications involving images, sounds, texts, medical data, physical measurements and Internet data, presented in videos on the Collège de France website. Each challenge provides labeled data as well as test data. Participants submit their predictions calculated on the test data to the website. The website calculates a score with a specified error metric. It provides a ranking for participants, enabling their results to be assessed in a wider community. Challenges start on January¹. An intermediate closing takes place in June, with an evaluation of predictions on new test data. The final closing takes place in December, with a prize-giving ceremony after each closing.

The challengedata.ens. fr website provides support for teachers wishing to use these challenges as projects for students in their courses. Teachers can register their course on the website and specify a list of projects that students can work on as part of the course. Teachers have access to the scores and reports posted by their students.

Each year, proposals for new challenges must be submitted in September, by sending an e-mail to challenge.data@ens.fr. They are validated by a team from the École normale supérieure.

The organization of these data challenges is supported by the CFM chair at the École normale supérieure and by the Fondation des Sciences Mathématiques de Paris.