Exercise: your first Classroom 50 assignment
Session 4 — Applied Data Science 2026
Reports 2 and 3 are handed in through Classroom 50. This is a practice assignment of exactly the same shape: you accept a link, clone the repository it gives you, commit and push. Nothing is marked.
It exists so that a problem with your account or your token turns up now, with three weeks to spare, and not on the evening Report 2 is due.
Start it in the session if you finish the main exercise early; otherwise do it at home before session 5.
Your task: follow the Classroom 50 manual to get the practice repository onto your laptop, then make three commits — one of them on GitHub rather than in RStudio — and push them.
Keep the manual open in a second tab. This sheet tells you what to do; the manual tells you how, with the exact buttons.
You need two things before the rest of this sheet works.
1. A GitHub account. Register at github.com — the free account is enough. Use your university email address. Choose a username you do not mind me reading: it appears in the name of every repository you hand in.
2. An invitation to the course organisation. Send me a Moodle message with your full name and your GitHub username — the username, not your email address and never your password. I then add you to the class, and GitHub emails you an invitation to applied-data-science-euf.
Until the invitation arrives, do the setup tutorial (Git and GitHub with RStudio) so that you are ready when it does. Then come back to this sheet.
1 Join the organisation
Accept the invitation to applied-data-science-euf — “Once per course”, step 4 in the manual.
Joining the organisation and accepting the assignment are two different things, and they happen in this order. If the assignment page later says Not a member yet, it is the first one that is missing.
2 Accept the assignment
Open the practice assignment link and accept it — manual, step 1:
The due date is Sunday 25 October, 23:59.
When you click Open repository, write down two things:
- The full name of your repository. Which three parts is it made of?
- Whose account does it live in — yours, or somewhere else?
3 Clone it
Clone the repository with File → New Project → Version Control → Git — manual, step 2.
You know it worked when the Git tab is there and the top-right corner of RStudio shows the repository’s name.
Compare with session 4’s main exercise. There, your project started on your laptop and use_github() sent it up to GitHub. Here, the repository started on GitHub and cloning brought it down — files, history, and the connection back to GitHub, so that Push knows where to go.
You can test that connection right away: click Pull. Already up to date. means RStudio reached GitHub and found nothing new.
4 Look before you change anything
Before your first commit, find out what you have been given:
- In the Files pane: which files came with the repository?
- In the Git tab, click the clock icon (History). How many commits are there already, and who made them?
- Open
.gitignore. Which files will Git never show you?
5 First commit: your name
Open practice.qmd. In the header, replace Your name with your name.
Save, then in the Git tab: tick the file (Stage), read the Diff, Commit with the message Add my name, Push.
Open your repository in the browser and reload. Is your name in practice.qmd? Is Add my name on the Commits list?
6 Second commit: a line of code
In practice.qmd, under Task 2, add a chunk that counts the hotels by number of stars:
hotels |>
count(stars)Render the document. Then look at the Git tab:
- Which file shows up as changed?
- The render just made a
practice.html. Does it show up? Why not?
Commit with a message that says what you added, and Push.
7 Third commit: on GitHub, then Pull
This time the change happens on GitHub, not on your laptop — as if you had worked on a library computer.
- In the browser, open
README.mdin your repository and click the pencil icon (Edit this file). - Add a line at the end, for example
Practice repository of <your name>. - Click Commit changes…, keep the suggested message, and confirm.
Back in RStudio, open README.md. Your new line is not there — your laptop does not know about that commit yet. Click Pull. Now it is.
If you had made another commit in RStudio and tried to Push without pulling, GitHub would have refused it — it has a commit your laptop does not. Optional task (a) lets you see that happen.
8 The check
Confirm all six:
If anything on the list did not work, tell me — on Moodle or in session 5. That is the point of the exercise. Say what you clicked and copy the exact error message.
9 If you finish early
- On GitHub, edit
README.mdonce more and commit there. - In RStudio, without pulling, change a sentence in
practice.qmd, commit, and Push.
Read what Git says. Then follow its advice: Pull, then Push. Was anything lost? Why was there no conflict?
Delete the whole Task 2 chunk from practice.qmd and save. Do not commit. Open the Diff and read what you just destroyed. Then, in the Git tab, select the file and click Revert.
Is the chunk back? What would have happened if you had committed and pushed the deletion first?