Your writing style is costly

Or, a case for using punctuation in Slack

You should use punctuation in Slack. You should also use complete sentences and proper grammar. You should expand acronyms[1] and — when communicating emotion — even mix in some emoji for effect. You should do that not just in Slack, but in all of your professional communication.

Written communication is hard, but in the digital world we work in it’s also vital. Sadly, the style of communication that services like Slack incentivize is awful.

To voice an opinion before the conversation moves on, you type fast and use abbreviations and hit send even with misspellings. You think one message at a time. You bounce between different threads and become easily distracted.

There are some obvious downsides to this fast and loose style. Most notably, it interrupts more productive work and deters deep thinking. But one large and often overlooked downside is the impact it has on others.


When you use an obscure initialism or take shortcuts on grammar and spelling, it may save you a couple seconds. The problem is those small savings are often outweighed by the cost born by your audience.

Every person who reads your message spends some finite period of time interpreting what you’re saying. Setting aside the possibility that a sloppy message might lead the reader to an incorrect interpretation, it’s harder to parse messages written hastily — messages with poor grammar, misspellings, minimal punctuation, obscure acronyms, or delivered a few words at a time.

As an example, assume you send the following message to a Slack channel with 10 other people in it.

anyone know the latest on cai

And further assume that “cai” refers to an internal project: Crusade Against Initialisms. By writing in all lower case, using an initialism to refer to the project, and omitting the question mark, you’ve saved yourself two words and a handful of extra keystrokes. Under the most generous assumptions, say that translates to five seconds in savings. That’s a lot!

But let’s now examine the impact the shortcuts have on your 10-person audience.

  • Two people thought “cai” was a typo and spent several moments trying to guess what you actually meant to type before realizing you were referring to the internal project. Cost: 20 seconds
  • Two people didn’t know what “cai” stood for. One spent three minutes tracking it down on the internal wiki, and the other sent a private message to another team member to ask. Cost: 4 minutes
  • One person ignored your ask because they didn’t realize it was a question when scanning the channel. Cost: Priceless
  • Five people understood what you meant but still had to mentally expand the initialism before internalizing your ask. Cost: 5 seconds

Your 5 seconds of savings amounted to roughly 4.5 minutes of cost spread across your audience. Sure, this is a contrived example and sure there are cases where the cost is lower, but the point stands: your communication shortcuts are costly.

In economics, this phenomena is referred to as a negative externality.

A negative externality is the cost that affects a third party who did not choose to incur that cost.

Every time you take a communication shortcut, you are inflicting a micro-externality on your audience. The more egregious the shortcut, the larger the externality; the larger your audience, the more times the externality is multiplied and the larger the overall cost.

So what?

If you’re communicating with a close friend and choose to use shorthand, you’re probably fine. Not only will your friend probably be accustomed to it (i.e. the externality will be small), but the audience is also small (i.e. the total cost will be small). In this case, it’s entirely possible your shorthand saves you more time than it costs your friend.

However, when you’re communicating in a one-to-many setting such as email or Slack, and particularly in a professional setting, sloppy writing[2] has real consequences. It prioritizes your time above the time of every other person that will be reading that message and might misinterpret your intent or tone. In aggregate, it is a net drain on productivity at your company.

So use proper spelling and grammar. Write out your entire thought before hitting send. Expand acronyms. Use punctuation.

A period, even at the end of “Do it,” communicates, “I’ve said everything I wanted to say.”

[1] For the sticklers out there, this includes initialisms as well as acronyms.
[2] The term "sloppy" might sound harsh, but I chose it deliberately. Not everyone speaks the company language (e.g. English) natively, and for them using proper spelling or grammar might be challenging to say the least. The argument here is scoped to people who have some degree of mastery over the language but are being sloppy with their written communication, which is to say "careless and unsystematic; excessively casual".

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