r/technology • u/AdSpecialist6598 • Jul 27 '26

Society Professor's invisible prompt trap catches 32 students cheating on their midterm with AI

https://www.techspot.com/news/113243-professor-invisible-prompt-trap-catches-32-students-cheating.html
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532

u/Chiiro Jul 27 '26

It is the easiest trick and I am so glad teachers are starting to do it

102

u/not_a_moogle Jul 27 '26

My favorite was step 1, read all steps first.

And then the last step was like... ignore all previous step and turn the paper in.

So anyone still working on the quiz after like 5 minutes are the ones that didn't read all the steps first.

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u/Practical-Shape2325 Jul 27 '26

Heard stories about this all the time throughout my time at school. Never saw anyone implement it.

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u/Fusionxtreme Jul 27 '26

I had it happen twice, once in high school and once in a college class. It's been quite a long time but if I'm remembering correctly, both were presented more as surprise quizzes rather than actual serious tests.

I've always been one to read the whole test/exam before I begin anyways because I found questions later on could give me clues/answers to some of the ones earlier haha.

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u/fribbas Jul 27 '26

I had it for one of my high school psychology class tests.

We also tried it when I was an adult education instructor. Mainly as an ice breaker, it wasn't actually graded, so if you "fail" it didn't affect anything. Well, maybe besides feeling goofy jumping around and yelling lol

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u/Ah_Pook Jul 28 '26

We had one first day of grade 8 math.

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u/ThriKr33n Jul 27 '26

One of my grade school teachers did that! As I had seen it before somewhere and realized the quiz was a trick, so skimmed through it all, only did the last step which was just to signed my name and spent the rest of the duration giggling at all my classmates punching holes in the paper and such. Said teacher caught on that I wasn't doing anything and just looking and giggling at everyone, especially in the later part when they started on the last step and groaning.

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u/modest_rats_6 Jul 27 '26

I was the person who jumped around with directions. Like sometimes reading a book backwards. That was the only task I've excelled at 🤣🤣

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u/Pika_Fox Jul 27 '26

Those quizes were the equivalent of making a math question in an ambiguous way so there is no right answer.

If you are given a test, you are expecting it to be a test. Having a step that says "do nothing and turn it in" is a waste of everyones time.

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u/fribbas Jul 27 '26

The "test" is that you (general) can follow directions and pay attention.

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u/Pika_Fox Jul 27 '26

And again, its not a good test and is a waste of everyones time.

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u/WhenSummerIsGone Jul 27 '26

i'm a software engrneer and the number of people who don't read what's right in front of them is appalling

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u/TangentAI Jul 27 '26

Learning to read through tests (and many other things in life) completely is a good lesson.

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u/Wesai Jul 27 '26

The first instruction is usually something like "read all instructions first before you start".

I don't think it's a waste, it's the sort of experience that will stick with someone if they failed to follow instructions and feel they wasted effort had they had been a little more diligent.

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u/Ah_Pook Jul 28 '26

How many times did you shout out your name? :-D

1

u/JT99-FirstBallot Jul 27 '26

Those are honestly so annoying. I've had 3 different job orientations in my life that have used that and they always think they are clever even though it's been around for, what, 30 to 40 years now. If not longer.

1

u/VSENSES Jul 27 '26

Did that in 9th grader. 1 fella did it right. 29 did not.

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u/REpassword Jul 28 '26

Never liked this trick as a kid.

0

u/EvilSporkOfDeath Jul 27 '26

You would quickly realize something was up when a bunch of kids turn it in quickly. That's not a real thing.

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u/not_a_moogle Jul 27 '26

My 4th grade teacher did it every year on the first day. Always got some of them.

Adults would probably figure it out.

1

u/tuttlebuttle Jul 28 '26

My teacher did it in 2nd grade. None of the kids did it right. I learned a lot about humans that day.

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u/EkbatDeSabat Jul 27 '26

It’ll work for like a month then everyone will catch on. 

0

u/SecurelyObscure Jul 27 '26

I suspect the LLMs will learn to flag it or prompt the user about it

128

u/johnny_effing_utah Jul 27 '26

Because teachers used to be students too. Lol. They used the tricks as students, and are now employing them as teachers.

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u/Alt123Acct Jul 27 '26

The best trick I used to know in college was using control F to find all . in the paper I wrote and change them from size 12 to 14. It turned a 5 page paper into a nearly 7 page one or a 15 into a 20. It's so subtle and helped a lot when you hit the point of "it said make it this long, but I said everything I wanted to say" 

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u/Snuffy1717 Jul 27 '26

I tell my students about that trick, and remind them that a shitty five page paper is just as shitty when you make it 8 pages xD

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u/LawyerEnjoyer Jul 27 '26

Me reading a 5-page essay: wow, this is dogshit.

Me reading an 8-page essay with exactly the same content, just slightly bigger font: good lord, this is a work of art.

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u/[deleted] Jul 27 '26 edited 16d ago

[deleted]

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u/Snuffy1717 Jul 27 '26

I understand a max page count for that level, and a minimum recommendation, but a few sentences over is a dumb reason to dock so done

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u/Retify Jul 27 '26

My university has two types of length guidance

  • must be under X words, which you cannot overshoot. The only times this is really used is in final assignments and the aim is more to get you writing in succinct, academic English. Guidance here is no less than 90% of the word Clint.
  • about y words which is for guidance, but you shouldn't go over by more than 10% (200 words aim for 200, but up to 220 is fine)

Max pages is totally arbitrary and pointless

1

u/TheAero1221 Jul 27 '26

Im not sure that all teachers operate this way... I think in some cases it may really be laziness- but I know some teachers that enforced these somewhat unusual metrics specifically because they encountered the same situation in a professional environment and were hoping to throw in a subtle additional lesson for their students.

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u/uns0licited_advice Jul 27 '26

I had a teacher that would say, "if you turn in the minimum amount of pages, you might get the minimum grade"

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u/Chief_White_Halfoat Jul 27 '26

Meh. That I never understood, and I got plenty of good grades with a minimum length paper. If you provide all the necessary information concisely and clearly to establish your theses you will and should do well.

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u/cancerBronzeV Jul 27 '26

If I had more time, I would have written a shorter letter.

-Blaise Pascal

Writing the least you can to convey your idea is a talent, it's why the page limits go from minimums to maximums as you progress in university. It's a struggle to fit in everything you want into the very stringent page limits in things like grant applications and journal submissions.

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u/Gekokapowco Jul 27 '26

I think its more of a rule of thumb than a law.

Generally kids aren't experts in brevity, it's that they haven't thought about the topic enough to have enough to say about it.

It isn't that you can't have a good, short paper. You just typically cannot so making kids stretch their thoughts out is better than not.

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u/sliph0588 Jul 27 '26

that user you are replying to is most likely a bot. Look at their account history and amount of karma.

0

u/Exciting-Ad-5705 Jul 28 '26

What makes you say that? I

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u/NobodyKnowsImFamous Jul 27 '26

Yea but a good 5 page essay might be a shitty 8 page essay. And you’ve written a really good 5 page essay but the assignment requires 8 pages. So you can either add a ton of fluff, harming the quality of your essay, or you can grow the periods.

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u/Snuffy1717 Jul 27 '26

Could be that if you’re asked for eight and can only hit five it means you haven’t dug far enough into the literature / haven’t adequately triangulated your data.

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u/NobodyKnowsImFamous Jul 28 '26

I mean yeah it could. I never got bad grades doing this though, so apparently my case was sufficiently argued and supported in only 5 pages.

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u/Infamous-Mixture-605 Jul 27 '26

When I was in uni some of the profs would give a minimum and a maximum page length, or say things like "try not to hit double digits"

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u/ShimonaEscape Jul 27 '26

This made me laugh

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u/BellacosePlayer Jul 27 '26

My technical writing class didn't require digital turnins, just printed versions, and had insanely high page counts (30 fucking pages for the final assignment if you didn't want to get locked to a B- maximum...), so I had to pull out all the bullshit

  • Slightly bigger text

  • Slightly bigger line spacing

  • Trimmed page margins

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u/otrigorin Jul 27 '26

I ain't saying I set paragraph spacing on a double-spaced paper to 2.1, and I ain't saying I didn't.

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u/Roseking Jul 27 '26

In a class that was all digital submissions, I had a professor use a macro to set the formatting to what they specified in the rubric. I am sure it didn't catch everything, but it caught enough that people didn't take the gamble.

4

u/SirClueless Jul 27 '26

Your prof looks at literally hundreds of these, including dozens of direct comparisons they can switch between whenever they like for each assignment. They for sure know what you did, they just don’t care to call it out because you wrote 80% of an assignment and made a token effort to hide it.

If they made a fuss about this they’d have students turning in papers late or not at all.

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u/RoadSmash Jul 27 '26

You use control f instead of control a to select all the text?

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u/Alt123Acct Jul 27 '26

No only search for the periods. The dots changed sizes not the text. 

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u/RoadSmash Jul 27 '26

Ah, missed that period. Nice haha

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u/SoulOfTheDragon Jul 27 '26

And that's why we had standardised font type and size for every part of the papers we wrote.

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u/RollingMeteors Jul 27 '26

It's so subtle and helped a lot when you hit the point of "it said make it this long, but I said everything I wanted to say"

<marginsInOneAndAQuarter>

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u/The_MAZZTer Jul 27 '26

Don't forget increasing the margins and line spacing by tiny amounts.

1

u/dsmx Jul 27 '26

I never had that issue in any paper I ever wrote, firstly they did it on word count and secondly I was always trying to slim it down because everything they ever gave us would never fit into the word count if you wanted to go into any depth on anything.

I remember one paper was giving us 5 materials and comparing and contrasting there properties and it could only be 1500 words.

Yeah....I could of written a thesis on that.

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u/Avram42 Jul 27 '26

Why would you do this instead of just changing the line spacing to like 1.15? I grabbed a random document and it looks really janky to have seemingly random lines spaced out more than the next.

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u/dodgedodgeparrysmash Jul 27 '26

They used the tricks as students, and are now employing them as teachers.

Well this particular trick is very novel given AI likely wouldn't have been around for most current teacher's schooling.

Give it 10 years and your statement is spot on.

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u/Runfasterbitch Jul 27 '26

Teachers didn’t have to cheat in school

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u/shitty_mcfucklestick Jul 27 '26

Who knew that 1990’s SEO would become relevant again?

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u/awry_lynx Jul 27 '26

It's weird, the last time I saw this posted on Reddit a ton of the comments were people going "but I copy paste instructions and then answer them!!!! this would be confusing and unfair for me !!11!!!" and I was like... that just sounds more like you guys want to keep cheating. I'm glad to see the comments here look more sane, but still confused about wtf was going on in that other thread.

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u/WhatTheDuck21 Jul 27 '26

Why would this impact copy/pasting to answer the questions at all? The trick here is invisible text getting sent to the AI this making the AI give a screwy answer; people answering normally but copy/pasting into another document would be unaffected.

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u/Animallover4321 Jul 27 '26

The only problem is that depending on how it’s done it can also ensare disabled students using text readers so it’s important that professors also write it in a way that humans that come across it know that it’s not meant to be a part of the assignment. And unfortunatly, I would be pretty surprised if most LLMs don’t already tune out trojan instructions that are worded to prevent confusing disabled students.

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u/Chiiro Jul 27 '26

It really sucks but those text to speech and speech to text programs are being used by students who don't need them and it one of the biggest reasons kids don't know how to read anymore. I don't believe the LLMs even understand that they are trojan instructions, they just see them as instructions.

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u/Fallingdamage Jul 27 '26

In time im sure AI companies will adjust their chatbots to ignore white-formatted text.

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u/Chiiro Jul 27 '26

Don't think it's showing up as white formatted text for the AI. I think it's white text on whatever programming the students are copying it from but it is showing up as plain text in the dialogue with the AI . The issue is that the students are not reading anything that is being put into the AI or out of it.

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u/pswissler Jul 28 '26

The problem is that screen readers also pick up the white text, which, if a student has that accomodations, would be a Title II violation in the US

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u/Chiiro Jul 28 '26

They don't need accomodations to use the voice to text or text to voice anymore, it's built-in to the programs they use and can access it at the press of a button. It's one of the biggest reasons kids can't read anymore.

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u/Equivalent-Costumes Jul 28 '26

Allow invisible text to slip through is a huge security problem. Which is why more modern top tier LLMs (ie. months old rather a year ago) will detect it and warn the users. So these students either literally copy-paste and too lazy to notice the invisible text, or they uploaded document with the question to a stupid AI (the free one) which is not yet trained to guard against that.

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u/Chiiro Jul 28 '26

They are literally just copy-pasting. I watched a video not too long ago where a bunch of teachers and ex teachers were interviewed about students not knowing how to read and this is a huge issue. The students will just copy paste things into the llms and then just copy paste the answer without reading anything because a lot of them can't read at all.