PSL Voices | 24h with Laetitia in the CPES - Data Sciences, Arts & Culture track

Published April 17, 2026

8AM 🌅

After a 45-minute journey in the subway, I arrive a bit early on the 'Amyot campus' in the 5^th district of Paris. I get to classroom 4 for my Data Science class. Today is the personal project day, that project will be the main grade of the semester. I decided to work on the evolution of moral transgression in Harry Potter fan fictions. I want to make this as good as possible so I ask questions to my professor on how I could gather the data that I want: I will have to use scraping, a technique that codes a program that allows you to automatically retrieve online data. The process sounds complicated, but it is actually quite simple when the professor gives examples, even for me who only started coding last year!

10AM 💬

We take a break and I discuss my weekend plans with my friends. Then we move on to a mathematics class. Mathematics are an important part in our curriculum, and we have two separate classes: algebra and analysis. Everyone has their preferences but today we’re doing analysis! Lately, we’ve been studying a chapter on derivation, that essentially follows up some classes we may have had in high school but delves deeper.  We also do in-class exercises, showing, for example, the solution to an equation, using the intermediate value theorem.

12:15PM 🍽️

It’s finally lunch break! I hurry and join my mentee who is a first-year student. First-year students are partnered with a second-year student that will help them adapt to the student life. It is also a great way to meet people! I’ve become good friends with my mentee and we eat together once a week. Today, we decided to eat in front of the Pantheon to enjoy the nice weather.

1:30PM ➗

Back to this morning’s mathematics class. We continue the exercises we had started before lunch. I even corrected a question on the board. I’m quite proud of that because I don’t often succeed in this class!

3PM 👩‍💻

We have a 45-minute break, which only happens on Wednesdays unfortunately. I connect on the remote meeting with my internship supervising team: in the second year, we need to complete a two-month internship to pass. I’ve had the opportunity to do mine in the Cognitive sciences department of the ENS, thanks to the UROP program). My internship is focused on why women do less scientific studies than men. Today, we are discussing analysis results that were conducted over the week and the next steps going forward. The team wants to send out a survey to scientific 'preparatory classes' students (selective postgraduate classes for the entrance in French “Grandes Ecoles”) and I’m in charge of writing a briefing note to the heads of the establishments to explain the project to them.

3:45PM 🗣️

I now head to my linguistics class where we study languages in different angles. We, for example, started off with sounds, that differ from one language to another. Today, we are working on notions we spoke about in yesterday’s lecture: we solve linguistic puzzles, which is a very playful way of learning. The purpose is to associate the name of numbers is Basque language to their corresponding number and identify the patterns. The first group to finish gets to correct the exercise, which is very motivating!

5:45PM 💆‍♀️

My day is over! I head home and since we start at 10:30AM tomorrow, I take the opportunity to work on my Data science project then watch an episode of my current favorite show. It’s important to detach yourself from work after a long day.

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