/scientific-prose-style

name: scientific-prose-style
description: "Prose-quality rules for writing scientific manuscript text: abstract, introduction, results, discussion. The headline rule is a strict em-dash budget: the long dash (—) is overused and reads as a stylistic tic, so cap it and rewrite with commas, colons, parentheses, or a period. Also caps semicolons and colons, the usual replacements, and covers hedging, sentence rhythm, paragraph openers, and AI-sounding prose (去 AI 味, AI 味重, sounds AI-generated) with an information test, a corpus-checked list of tells and a detection script. Load whenever drafting or revising manuscript prose (not figures; that is figure-planner)."
license: Apache-2.0

scientific-prose-style

Rules for the *prose* of a scientific paper — the sentences of the abstract, introduction, results, and discussion. Load this whenever you draft or revise manuscript text. (Figure planning lives in `figure-planner`; this skill is about words on the page.)

This skill owns punctuation, rhythm and word-level tells, and it runs last. When a passage is hard to follow for reasons punctuation cannot fix, such as an unstable claim, a missing evidence link, or a paragraph whose job is unclear, fix that first with `manuscript-optimizer` or `scientific-writing`. Re-punctuating a sentence whose scientific role is wrong does not make it readable, and polishing a drifted Review before its `review-article-architecture` drift audit makes the drift harder to see.

One layer sits directly above this one. `anti-defensive-writing` owns authorial posture at the paragraph level: what a paragraph leads with, where a caveat sits, and whether a sentence exists to advance the argument or to pre-empt an objection. Run it first. Stripping defensive scaffolding rewrites paragraph openers and sentence boundaries, which is exactly what Rule 3 and Rule 5 below then have to settle, so running this skill first means doing that work twice. Rule 3 here calibrates hedges within a sentence; deciding whether the hedge should exist at all belongs upstairs.

Rule 1: Em-dash budget (the headline rule)

The long em-dash (`—`) is the single most overused mark in generated scientific prose. It feels punchy in isolation but a reader hits three or four per paragraph and it reads as a stylistic tic, not as writing. **Cap it.**

• **At most one em-dash per paragraph, and none in the abstract.** If a sentence

already has one, the next clause that wants a dash gets a different mark.

• **Never use a *pair* of em-dashes to bracket an aside** if a comma pair or

parentheses would do — the double dash is the worst offender.

• Prefer, in rough order: **comma** (mild pause), **colon** (a list or an

expansion of what precedes), **parentheses** (a true aside the sentence reads fine without), or **split into two sentences** (the strongest fix for a long dash-spliced line).

Substitution table

| Em-dash use | Replace with | Example fix | |---|---|---| | Pause before a summary/payoff | colon | `...never been tested — this is our entry point.` → `...never been tested. This is our entry point.` | | Bracketed aside (pair of dashes) | commas or parentheses | `no model — including ESM — beats chance` → `no model, including ESM, beats chance` | | Appositive / renaming | comma | `allele-resolution prediction — telling apart variants` → `allele-resolution prediction, i.e. telling variants apart,` | | Abrupt contrast | period + connective, or "but" | `real but sub-threshold — the effect vanishes` → `real but sub-threshold: the effect vanishes` | | Range or span (this is fine) | keep an **en-dash** `–`, not em | `370–1000 cells` stays `370–1000` |

Before → after (from a real over-dashed abstract)

**Before (5 em-dashes, tic-heavy):** > Starting from the hardest instance of the problem — allele-resolution > prediction, distinguishing many coding variants of the same gene — we assemble > a benchmark, and find this is a measurement limit, not a model limit — a > split-half floor shows the distance is no larger than sampling noise.

**After (0 em-dashes, same content):** > We start from the hardest instance of the problem: allele-resolution > prediction, which distinguishes many coding variants of the same gene. On the > benchmark we assemble, the ceiling turns out to be a measurement limit rather > than a model limit. A split-half floor analysis shows the perturbation-versus- > control distance is no larger than the sampling noise between two halves of a > variant's own cells.

Note what the rewrite does: promotes one clause to its own sentence, turns the bracketed aside into a relative clause, and swaps the contrast dash for "rather than." The prose is calmer and each sentence carries one idea.

Rule 2: Don't trade the dash for a colon or semicolon tic

Colons and semicolons are the natural replacements, and the same overuse applies.

• **Colons:** at most one per sentence. If every sentence in a paragraph ends

`...: <expansion>`, you have just moved the tic.

• **Semicolons:** none in the abstract, and at most one per paragraph elsewhere.

Published prose rarely uses them. In `paper-workflow`'s section evidence, 3 of 23 typeset method-paper abstracts and 1 of 12 `Nature` abstracts have one, and three quarters of the Results and Discussion paragraphs have none. Two clauses joined by a semicolon are usually two sentences. Semicolons that separate list items already containing commas, or statistics inside parentheses, do not count.

Vary the repair. Most become periods, some become commas or a plain connective (`and`, `but`, `so`).

Rule 3: Hedge once, not thrice

Scientific prose stacks hedges (`may possibly suggest that ... could in principle ...`). State the claim with one qualifier and the confidence level, then stop. `These results suggest X` — not `These results may tentatively be taken to suggest that X could hold`.

Rule 4: Vary sentence length, one idea per sentence

A paragraph of uniformly long, claus