Wanted: Advice from CS teachers
When #teaching a group of students new to coding I've noticed that my students who are normally very good about not calling out during class will shout "it's not working!" the moment their code hits an error and fails to run. They want me to fix it right away. This makes for too many interruptions since I'm easy to nerd snipe in this way.
I think I need to let them know that fixing errors that keep the code from running is literally what I'm trying to teach.
Example of the problem:
Me: "OK everyone. Next we'll make this into a function so we can simply call it each time-"
Student 1: "It won't work." (student who wouldn't interrupt like this normally)
Student 2: "Mine's broken too!"
Student 3: "It says error. I have the EXACT same thing as you but it's not working."
This makes me feel overloaded and grouchy. Too many questions at once. What I want them to do is wait until the explanation is done and ask when I'm walking around. #CSEdu
I think they become anxious when their code isn't working the same as what I have up on the projector and they want to get it fixed RIGHT AWAY so they won't fall behind.
Then when one of them starts calling out they all do it.
I may take some time to explain this.
This never happens when I'm teaching math. Something about coding makes them forget some of their manners, and become less self-sufficient. "It's broke! I'm helpless!"
What is that about?
My students aren't lazy, but they *can* be a little perfectionist: scared to take risks or sit with not having the answer right away.
They are really upset when their code won't run... but staying calm and *systematically* looking for the cause of the problem, knowing that if you just work through the tree of possible causes you will find it is not something they are good at.
I think I need to teach this.
Maybe I will give them some broken code and we will find the errors together.
So Your Code Won't Run
1. There *is* an error in your code. It's probably just a typo. You can find it by looking for it in a calm, systematic way.
2. The error will make sense. It's not random. The computer does not "just hate you"
3. Read the error message. The error message *tries* to help you, but it's just a computer so YOUR HUMAN INTELLIGENCE may be needed to find the real source of error.
4. Every programmer makes errors. Great programmers can find and fix them.
1/
Things to Try:
* look for typos
* look at what the error message indicates.
If these don't work consider reverting your last changes to the last working version of your code. Then try making the changes again, but be more careful.
If you can't revert the changes, start removing bits of the code systematically. Remove the things you think might cause the error and run the code again. Isolate the change or code that causes the problem.
You can be a great programmer.
2/2
@futurebird I gave my students code with errors in it and had them fix it. But they do have to be at a certain level to be able to do that.
I stole this idea from the Java certification exams, which had code examples that would get most people fired.
@futurebird I usually have clear me/them speaking parts in the course. While I speak, they listen, which I enforce up to the last whisper.
Also, the "me" parts only take 15-20 minutes each, then it's time for questions, https://github.com/ineiti/livequiz, or other interactions.
For the exercise sections, the "me" parts are of course much shorter.
"I usually have clear me/them speaking parts in the course. While I speak, they listen, which I enforce up to the last whisper.
Also, the "me" parts only take 15-20 minutes each"
This is how I normally teach (although with middle school students I keep "me" bits to under 8 min each) this is why it's so annoying when they call out during these sections. Something they wouldn't ever do normally.
Something about coding and seeing the error makes them not see it as "time to listen"
@futurebird I'm also interested how to add LLMs to the mix: how to use them in a way we use IDEs now: we still know how to program/read code, but IDEs are so useful.
This will add another level to the me/them, where sometimes I'd want them to use LLMs, other times not.
But first I need to convince the school it's a good approach: I'm an external teacher, and as such have very little influence...
@jessienab One of the professors taught C++ in Notepad, because he said that IDEs are an abomination and distract from the real programming...
I'm actually quite happy with LLMs, they're very limited, and there is lots of stuff I cannot do with them. But on some things they really shine, and I think part of it is because I have a lot of background knowledge to link what they tell me.
So how do we present this new tech to kids in a way that they still think?
So how do we present this new tech to kids in a way that they still think?
We don't!!!! argh. there's so many examples of WHY it's been bad to use AI with programming, and to introduce it to children who's minds are so ... influenceable, is NOT a good idea!!
It's also becoming more and more clear that the general idea of using AI generated code is not only affecting the apps using that code, but the human operators too:
https://www.theregister.com/2025/06/18/is_ai_changing_our_brains/
Plus, some of these AI agents have security issues:
https://cy.md/opencode-rce/
And in general, and I've seen this myself... AI generated code is often flakey and full of errors:
https://floofy.tech/@arch/115881804200692137
One of the professors taught C++ in Notepad, because he said that IDEs are an abomination and distract from the real programming...
Your professor choosing to use Notepad vs an IDE is a matter of preference, wherein there is a notable loss of benefits with one vs the other; additionally, where one may prefer to not be distracted from the process of creation.
There's no "matter of preference" in using AI LLMs to generate your code, vs... coding it yourself. You're either coding with AI, or not in that case... they're not comparable.
Nice to hear you found something you enjoy, but please consider all the (proven) negatives it's bringing to the world, let alone to yourself, before you foist it onto others.
bye for now
@[email protected]
I think LLMs are tricky, it would require being able to tell whether it's giving you something useful or not, which I suspect could be overwhelming to students.
And they're so verbose that I think it would suck out a lot of time from students just to try to read and understand what the LLM said, much less figure out if it was accurate or not.
Sometimes LLMs are not very good for larger projects due to limited context size, so it won't work as well in all industry use cases either.
@coolcoder360 currently I have an idea how to use LLMs to get students to explore subjects. But there definitely has to be some time without LLMs where the students have to learn on their own.
I hope I get the time to do a writeup of what I think might work...
@futurebird @ligasser Teaching math is a dyad: You or the student are communicating. In coding, it's triadic: you, the student, and the error message -- which won't always appear in calming, student-friendly language.
When an error message interrupts you, the dynamic shifts. Students feel prompted to react to the sudden problem immediately.
Yes, that's exactly what I did! I already posted a couple of answers, but after looking at the whole thread I realized I didn't really understand the question. Yes, I think this is the answer to the question.
@futurebird You probably already know @b0rk‘s Pocked Guide to Debugging. The thing I love so much about it is how she cherishes the bug, instead of squashing it (in the illustrations too). I love this attitude. Not sure if students can learn to think that way? There is a beautiful poster too:
📰 https://wizardzines.com/zines/debugging-guide/
🖼️ https://store.wizardzines.com/products/poster-debugging-manifesto
Also: If you see pages and pages of errors, start by looking at the first error message. Often, that's the cause of all the others. Students sometimes just give up when confronted with a wall of errors.
@futurebird Just an idea but what about "switching" students around so they have to check someone else's code?
I used to do that with my students, asking them to grade each other papers.
It's always easier to see others' mistakes and it flatters their ego... I mean, self-confidence.
Also it's a sneaky way to make them realize that teaching is NOT easy.😉
@futurebird Also, I've noticed that learner programmers very rarely read the error messages with any level of attention.
Ooh, you could do a reverse challenge.... provide them with the error message and have them write the code that produces it!
@RogerBW @futurebird (some) C coders have a saying:
If the compiler emits an error, then your code can't run;
If the compiler emits a warning, then your code won't run, at least not the way you expect it to;
If the compiler emits no errors and no warnings, then it's high time you updated your compiler.
@futurebird > The error will make sense.
Have you heard of this thing called C++?
Yeah...
what I'm trying to convey is that there is a *reason* why the code isn't working and it will make sense in the context of the rules the got dang computer is trying to follow.
It might be annoying or silly, but it will "make sense"
@mansr @futurebird my highschool programming class was C++ based, but it was a joke. It was paint by numbers and we didn't learn programming.
The main thing I learned in that class was that Gmail existed and my classmates sent me an invitation to use it. Because he was checking his email during class time.
It's probably a missing or extra comma, quote, or paren.
"looking for it in a calm, systematic way" after the requisite freak-out & meltdown....
Thanks this is really helpful. We teach a graduate class on quantitative cell biology based in python. Many ppl don’t have prior coding experience, we probably need a section like this.
@futurebird This is what I would have suggested. Introduce the compiler, explain that you will encounter errors, but the error messages are designed to be as helpful as they can be.
(If you're using Python, error messages have been worked on over the last few major releases, with teaching particularly in mind, so it's worth using the most recent.)
"The error message *tries* to help you": the error message was written by people who had no interest in helping you
@futurebird
I've been a professional software engineer for over a decade now. I still make errors.
What's interesting is that at a certain level it's possible to write code that in isolation works exactly as you want it to, but it doesn't work in combination with the rest of the existing code.
But I also have tools to help me. My IDE checks for typos or syntax errors for me and flags them. It suggests solutions and offers to apply them. I have build tools written by other engineers to catch problems I might not have ever thought about.
No one person knows everything, but anyone can learn enough to be effective
@futurebird Yes, when I taught young adults I had an explicit section, right after the first ones that gave them a taste of success, on reading error messages.
Showed an error -- intimidating, eh? But we can pick out parts. Line number, file, error type, message, and a traceback. Highlight those as I pointed them out. New raw error message: hey, same structure! Can we pick out the line number? etc.
1/
@futurebird
So that was step one, teach their eyes to pick info from the error text, instead of sliding off it. Next step teach them to see error as a call for their action. I did this by running through 2-3 common errors and the action, repeating 'WHEN I see an X error, THEN I do Y' language.
WHEN I see a NameError, THEN I read the error, look up the line, and look for a mistyped name.
WHEN I see a SyntaxError, THEN I double-check my quote marks / parentheses / colons.
2/
Also IndentError, KeyError, and IndexError.
(Optional: 'hunt the Big Five': can they deliberately make code that has this error? and then fix it?)
Finally TypeError, for which more than the previous errors the fix depends on what you were doing. New phrase: 'I THOUGHT I had a number, but I HAVE a string. Can I change what I HAVE, or should I change what I THINK?"
Change what I have: int(my_string)
Change what I think: Ah, x can also be a string. `if type(my_x) is str: ...`
3/
Okay, last bits, sorry for going on so long!
1. My inspiration was Software Carpentry's module on reading errors. https://swcarpentry.github.io/python-novice-inflammation-2.7/07-errors.html
2. I also taught them about 'rubber ducking'. Made it all conspiratorial, let them in on the secret, tell them the pros do this. (We do!) The secret is: draw a little duck, and when you get errors explain your problem to the duck. Duck is simple duck, so explain every detail. Often, because you explain it, you'll realise how to fix it! 4/4
> Maybe I will give them some broken code and we will find the errors together.
I think this is an excellent idea!
@futurebird Not a teacher, but that sounds great.
Learning what error messages are and what they can tell you is so important. It's so different to many other subjects where you don't get that kind of information when something goes wrong, plus they will have grown up using computers of various kinds where an error message really is just a cryptic string of words that they can't do anything with.
@futurebird assigning code broken in specific ways & having a rubric for teaching the troubleshooting sounds like it should be SOP for coding courses, is this not normally part of the curriculum? 🤔
(def not dumping on you, asking as an Old who is a self-taught potato coder who never did a CS degree & feels like the way I learned basically anything that I do know was: type it in from a magazine or other source / modify working code that’s similar to what I need -> make mistakes in transcription / tweaks -> code doesn’t run or runs with errors -> troubleshoot the mistakes -> learn stuff 🙃)
At the university we had this maybe once.
But then, to quote a professor: "You are learning 'computer science' here. 'Programming' is something that you should either already know or learn in your free time."
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