Supervisors & feedback

“My supervisor says it needs ‘more depth.’ What does that mean?”

Translating the five most common vague comments into concrete fixes.

“Be more critical.” “This needs more depth.” “So what?” “It’s not quite PhD level.” These land hard and point nowhere; you feel the criticism without knowing what to change. Each has a concrete meaning, and a concrete fix.

By Heidi Andersén, MD, PhD · Updated 18 July 2026 · 7 min read

“I normally couldn’t even work for at least half a day after reading my supervisor’s comments… they were very demoralising.” — a PhD student on vague, blunt feedback

The problemVague feedback feels like a verdict on you.

The reason “be more critical” stings is that, with nothing concrete attached, your mind fills the gap with the worst reading: I’m not good enough. But these phrases are usually shorthand for a specific, fixable structural problem your supervisor sees so often they have stopped spelling it out. Decoding them turns a demoralising note into a task, and a task you can finish is the fastest way out of the spiral.

You cannot fix what you cannot name. Guessing at vague feedback wastes weeks and often fixes the wrong thing, which reads as “didn’t take the comment on board” and deepens the tension. Naming what the phrase asks for lets you make the specific change, and lets you ask a follow-up question that makes you look engaged, not lost.

✎“I’m not good enough” is what you hear. It is not what they wrote.

Common mistakesFour ways decoding goes wrong

Reading it as a character judgement. “Not PhD level” is about the argument on the page, not your worth. Treat it as structural.
Adding words instead of adding thought. “More depth” rarely means “longer.” A longer paragraph that still only describes is not deeper.
Guessing silently for weeks. A five-minute clarifying question beats a fortnight spent fixing the wrong thing.
Asking “what do you mean?” with nothing attached. An open plea invites another vague answer. Bring a specific interpretation to react to.

The translationsWhat the five phrases ask

Vague comment, and the concrete fix

“Be more critical.” Stop summarising sources and start evaluating them. Where do they disagree, what are their weaknesses, and what do you conclude from the tension? Add your judgement, not more citations.
“This needs more depth.” You described what happened; add why and so what. Trace the mechanism, the implications, and the connection to your argument, not more length.
“So what?” The passage is true but its relevance is unstated. Make the link to your research question explicit.
“It’s not quite PhD level.” Usually the work reports rather than argues, or accepts the literature rather than positioning against it. Add a claim of your own that the chapter defends.
“This is descriptive.” You have told the reader what happened; now interpret it. Move from an account to an argument with a point that could be wrong.

The follow-upAsk for the specific without looking lost

The strongest move is to bring an interpretation and a candidate fix, then ask a yes-or-no question. Not “what did you mean by more critical?” but: “I read ‘be more critical’ as this: I’m summarising these three studies but not weighing them against each other. My plan is to add a paragraph comparing their methods and stating which I find more convincing, and why. Is that the direction you meant?” That shows you engaged, gives your supervisor something concrete to confirm or redirect, and turns a vague note into a shared plan in two minutes.

ChecklistDecode any vague comment

Four steps from sting to task

Write the exact phrase, and assume it is structural, not personal.
Name the most likely structural meaning (describe vs argue, what vs why, relevance).
Write the specific change you think it asks for.
Draft a one-line yes-or-no follow-up with your interpretation attached, then make the change and confirm it lands.

If you also supervise, or want to understand why feedback comes out this way, the companion piece is written from the other chair: what supervisors mean when they say the work is not ready.