Science Style Guide: Abbreviations

This post is part of my ongoing scientific style guideline series.

Textual compression techniques (TCDs) are used more and more in science writing. TCDs come in various forms, including truncation (e.g. mi for mile), acronyms (lol for laughing out loud), syllabic acronyms (covid for coronavirus disease), contraction (int’l for international), and others. The primary benefit of using TCDs in writing is to reduce text length. This is especially useful in contexts where space is limited, such as tables and charts, as well as when a long word or phrase is repeated multiple times. Another reason to use a TCD is to create a new semantic unit that is more practical to use than the long version. For instance, the TCD laser is both more convenient and more recognizable than the original light amplification by the stimulated emission of radiation.

Okay. Look at that paragraph without reading it. Does anything stand out?

I made up the phrase textual compression device and its acronym TCD. They simply mean “abbreviation,” which is what I would have used if I weren’t trying to illustrate the following points:

  • Abbreviations can be distracting. Readers expect words, and things that look less like words — capitalized acronyms, random apostrophes in the middle of a word — will stand out, as does TCD above. Used sparingly, that can be good, to draw attention to something. But in large quantities, it’s jarring.
    • It’s even worse when multiple different abbreviations are in close proximity, or when similar abbreviations are used (e.g. TCRµ and TCRδ, which come up all the time in a paper I’m reading).
  • More importantly, abbreviations demand cognitive effort. If the reader doesn’t already know an abbreviation (for instance because you made it up), they have to spend some energy learning it. You’d probably prefer them to expend that energy understanding your paper instead.
    • Worse, they might have to interrupt their reading to go back to where you defined the abbreviation, or to look it up online. (A nice opportunity to quit reading your paper altogether.)

Humans don’t read like computers. You can’t just “declare” an abbreviation as you would a variable in code, and assume that from now on your reader knows what it stands for. It’s quite likely that readers will skim your piece, or jump directly to a specific section (e.g. results), in which case they can miss the definition. Even if they do read it, they might forget — in a typical paper, there’s a lot of information to remember.

Of course, abbreviations can be useful, as the TCD paragraph laboriously explains. But the benefits are rather minor. On computer screens, which is where your scientific writing will almost always be read, space is virtually unlimited. (Figures and tables remain a good use case, as long as the abbreviations are easily readable in the caption.) Creating a new, more practical way to call a thing (e.g. laser) can be quite useful, but again, only if used sparingly, for important concepts.

Overall, the benefits of abbreviations are much greater for the writer than for the reader — which is exactly the opposite of what we want as per the Minimum Reading Friction principle.

The other principle, Low-Hanging Fruit, says that the best improvements are those that require little writing skill to implement. Abbreviation minimization fits the bill. In most cases, you can improve the text just by replacing the abbreviation with:

  • The spelled-out version (textual compression device instead of TCD)
  • A synonym (abbreviation instead of TCD / textual compression device)
  • The core noun of the abbreviated phrase (e.g. device; not the best example but you get the idea. It will usually be clear in context what you refer to, unless you’re talking about many different types of devices).

Sometimes you’ll need to perform a bit more rephrasing, but rarely will you have to perform major rephrasing due to abbreviations. If you do, that’s probably a sign that the original text was awfully painful to read.


  • Coin new abbreviations as rarely as possible.
    • If you must coin new abbreviations, make sure they’re short, pronounceable, and memorable. Don’t hesitate to repeat their meaning multiple times — you’re teaching your readers a new word.
  • Generally prefer the use of spelled-out versions, core nouns, or synonyms.
  • Avoid using multiple different abbreviations in close proximity.
  • Abbreviations that are generally well-known, such as DNA, can be used as much as you want. A good way to tell is if they’re included in dictionaries.
  • If you can’t avoid using several uncommon or new abbreviations, it can be helpful to draw attention to them, so that readers are warned that they will have a better time if they make sure they learn the new terms.
    • This could take the form of a short glossary at the beginning, making it easy to look up definitions during reading.