Try this before you submit your next lab report: paste it into a chat and ask the model to grade you like a TA who’s seen a thousand of these and isn’t impressed yet.
A mechanical engineering student on r/PromptEngineering (shoutout u/InsuranceNeither903) built exactly that. Not a report writer. A report interrogator. Here’s the setup.
⚙️ The Prompt
- Paste your method, results, and discussion into the chat.
- Tell it: “You are a tough but fair grading TA. Do not fix my writing.”
- Ask it to list every assumption you made but never stated.
- Ask it to flag any result missing error sources or uncertainty.
- Ask it to check units and dimensional consistency.
- Ask it for the 3 questions a grader would write in the margin.
- Ask it where your discussion claims more than your data actually supports.
Then you go fix what it flags. Yourself. That last part matters more than it sounds.
🔍 What The Results Mean
If it comes back clean, you’re probably fine, but check the units anyway. One redditor found a pressure listed in kPa that quietly didn’t match the rest of the calc, worth 5 points on a fluids report.
If it flags unstated assumptions, that’s your biggest leak. This is the exact spot where a grader stops reading generously and starts circling things in red.
If it says your discussion overreaches, tighten the claim to what the data actually shows. That’s an easy fix once you see it.
💡 Extra Tip
One commenter suggested turning step 3 into an “assumption ledger”: have the model list every assumption in a table with a column for whether you stated it explicitly. Forces you to own each one instead of skimming past it.
And don’t let it touch your actual writing. The moment you let it draft, you lose the engineering judgment that’s supposed to be yours. Keep that part. Outsource the blind spot, not the brain.
🚀 Try It
Next report you write, run it through this before you hit submit. Takes less time than proofreading and catches things proofreading never will 🎯
Frequently Asked Questions
Q: The prompt keeps flagging obvious stuff like “gravity exists.” How do I filter out trivial assumptions?
Try adding this to your prompt: “Do not invent a missing assumption merely because one is common in this type of lab. Label assumptions as Unsupported, Supported, or Unclear only if the report text actually reveals a decision point or gap.” One reader also recommends ranking flagged assumptions by grading impact (critical, material, minor) so you focus on what actually costs points, not textbook edge cases.
Q: Should I use an assumption ledger format?
If you’re getting generic checklists back, yes. Instead of a loose list, have the prompt organize findings into four categories: (1) measurement/setup, (2) model or equation, (3) boundary/environmental conditions, and (4) interpretation. For each, quote the exact sentence that triggered it, state the suspected assumption, explain why it changes results, and flag the severity. This keeps output focused and actionable instead of exhaustive.
Q: Can I use this approach for problem sets, essays, or other assignments?
Absolutely. The core idea, interrogating your own work before the grader does, scales to any assignment where unstated assumptions, overreach, or logic gaps cost points. Adapt the categories to fit: essays might focus on claim support and logical jumps instead of units; problem sets on boundary conditions and approximations. The “don’t fix, interrogate” boundary is what matters.
Q: The prompt flagged something I think is fine. What now?
That’s the point, you decide. The prompt is good at spotting gaps; it’s not good at engineering judgment. If you disagree with a flag, defend it clearly in your report (or in the margin for the TA). Better to pick your battles beforehand than argue after you’re already graded.
Q: Should I mention assumptions and limitations the prompt catches in my actual report?
Yes, but in the right place. Assumptions belong in your Methods section (“We assumed constant pressure to simplify…”). Limitations belong in Discussion (“Our model didn’t account for friction, which likely…”). Mixing them signals sloppy thinking to a grader. Use the prompt to surface both, then place each deliberately.
Here’s a prompt that interrogates your lab report the way a TA will, so you fix the holes an ai report generator would leave
by u/InsuranceNeither903 in PromptEngineering