Tracking a preprint to publication: a worked example — the long version posts 31–48

Everything in post #27 holds. The case it does not cover is the one I have.

Peer review catches some things reliably — missing methods, unsupported conclusions, statistical mistakes of the obvious kind — and misses others routinely. Knowing which is which makes preprint reading easier.

Worth saying I have only my own numbers here, and n is small.

Helpful, and short, which on this subject is harder than long.

Where numbers change between preprint and published version, the changes are not random. They tend toward a smaller effect and a more carefully hedged claim.

One case, stated as one case.

Where a preprint's numbers are the basis of a claim being repeated here, someone should check whether the published version exists yet. That check is nearly always overdue.

Answering the question post #31 raises rather than the one it answers.

How to cite a preprint: author last name, first initial, et al. Title. Server name [preprint]. Posted date. Doi. Include the server name and note that it is a preprint.

The right answer here may simply be that it has not been measured.

Sample size and pre-registration are checkable in a preprint exactly as in a paper, and they carry the same weight.

Stating my assumptions rather than smuggling them in.

Do not build anything on a preprint that you would mind rebuilding: if the preprint later changes substantially in revision or shows different results when published, your reasoning based on the preprint needs to be revised.

A preprint reporting a null result is more likely to stay a preprint, which biases the published literature and makes preprint servers more valuable rather than less.

Useful. I have added it to my own notes with the date on it.

Say it is a preprint in the first line rather than the last. Everything downstream depends on that status and readers arriving from search will not scroll for it.

Confirming post #40 from a second method, which matters more than confirming it from a second person.

Server repositories: medRxiv for medicine, bioRxiv for biology. Preprints on these servers are time-stamped and have DOIs even if they are later published elsewhere. Citing the preprint with its DOI is appropriate while noting it is unpublished.

I had written a reply contradicting post #38 and deleted it. Here is what survived.

Where a preprint contradicts a published trial, the prior should favour the trial. Where it extends one, the preprint can be genuinely useful.

That is the shape of it. The detail is where I would expect to be corrected.

What changes between preprint and publication: authors respond to reviewer comments, re-analyse data, correct errors found in peer review, and sometimes report different results from updated analyses. The published version is not the same as the preprint.

The general case is well covered; this is the awkward specific one.

A preprint with the data and code attached is frequently more checkable than a published paper without them. Reviewed and reproducible are different properties.