A summary of a paper is only worth writing if a later version of you can act on it. Most summaries fail that test. They are either a second abstract, too vague to use, or a wall of notes as long as the paper itself. A good summary is short, specific, and built so you can trust it months from now without reopening the source.
Lead with the one claim
Start with the single thing the paper is asking you to believe, in one plain sentence of your own. Not the topic, not the method, the claim. Everything else in your summary hangs off this. If you cannot write it, you have not finished reading, and no amount of note-taking will cover for that. Pulling out that one claim is the core skill behind reading a paper well in the first place.
Keep five things, cut the rest
A summary you will actually reuse holds five things and drops everything else:
- The claim, in one sentence.
- The evidence: what was measured, on what, and how. A result on fifty samples in one lab is a different thing from one across ten thousand, and your future self needs to know which it was.
- The strength: how large or convincing the effect is, not just that it reached significance.
- One real limitation, usually the one the authors half-admit in the discussion.
- Why it matters to you: the reason you are keeping this at all.
Five short lines. If a detail does not change how much you would trust or use the finding, it does not belong in the summary.
Write it for future-you
Write in plain words, in your own voice, as if explaining the paper to a colleague over coffee. Jargon you copied without understanding will read as noise later. The compression is the point: if you cannot say the paper simply, you do not yet understand it, and the summary has just told you so while it is still easy to fix.
Where it pays off
A summary written this way does three jobs. Writing it from memory is itself an act of recall, which is how you keep what you read instead of losing it. Months later it lets you reuse the paper, in a draft or an argument, without rereading the whole thing. And because it is plain and specific, it is something you can actually hand to someone else. A paper you have summarised this well is a paper you own.