Obvious unhelpful comments usually consist of abusive and negative comments as well as completely irrelevant ones and conversational ones. Those kind of comments are easy to spot.

But what about "incomplete" comments? Ones where someone is trying to make a valid argument but is incomplete and seems off topic.

One example is from this question. One user explains in the comments that travelling back in time is impossible due to the Second Law of Thermodynamics. The person asking the question doesn't fully understand and wonders if "information" follows this same law. Then a commenter says:

A photon is also thermodynamically constrained.

Although is may seem obvious to some that if any form of information could travel in time, it would be light; but the connection between information and photons is missing. It would sound much more relevant if the (somewhat) obvious had been stated. I tried to complete their argument in a comment of my own:

Information has to take some physical form, even if you use light, as @YuzurihaInori said, photons obey the laws of thermodynamics. So like mechanical messages, photon can't travel back in time.

But is this a case where that comment about the photons can be flagged? Can it be considered "unhelpful" if, with a few extra words, it would be fine?

  • 5
    $\begingroup$ They can, but should they? I think that it's $\endgroup$ Mar 12, 2018 at 15:01
  • $\begingroup$ I'm not sure if it's really "unhelpful" even though it isn't explicit. It still provides information that may help OP; but definitely isn't a complete answer. $\endgroup$
    – JMac
    Mar 12, 2018 at 15:15
  • $\begingroup$ So these kinds of comments aren't deserving of a flag? $\endgroup$
    – Niamh O'SS
    Mar 12, 2018 at 15:37

1 Answer 1


In general I'd say no, the fact that a comment is incomplete is not inherently a reason to flag it. If it's so incomplete that it's not even clear what it has to do with the question or answer, though, then that probably warrants a flag. There's a judgment call to be made here, and different people may disagree somewhat.

But I think a better way to approach this is to consider whether the comment is trying to do what comments are supposed to do, which is to suggest an improvement or request a clarification to their parent post. I think in many cases, you'll find that comments that look like they may be incomplete are trying to do something else, like offering up an answer (or partial answer), and in those cases you can flag them on that basis without even caring whether the comment is really complete.


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