Battle of the Word Nerds: AP vs. Chicago

Molly McCowan Style Guides Leave a Comment

Before I became a freelance editor, I worked at a music magazine that used the AP Stylebook as its style bible. I absorbed many of AP style’s idiosyncrasies—like always capitalizing the word after a colon if it starts a complete sentence—as fact.

I always replaced “over” with “more than” when referring to a greater numerical value, as in: “Tunisian scientists have been studying nematode behavior for over more than 35 years.” (Interestingly, the head honchos at AP changed this rule back in March 2014, and they now allow “over” to be used in these cases.)

When I started freelance editing, however, the world of style guides opened up to me. I voraciously consumed, as only a word nerd could, every style guide I could get my hands on, in order to teach myself the differences between them.

Most of my clients at the time were using APA or the Chicago Manual of Style, so I focused heavily on those two. Lo and behold, I found my personal preferences shifting from AP…to Chicago.

dark side

Here are two reasons why I prefer Chicago style to AP style.

1. The Oxford (serial) comma

That’s right, I’m going there. As any copyeditor knows, the AP and Chicago cults are fiercely divided on this issue, so I don’t discuss this topic lightly. Let’s understand the basics.

In AP style, a comma before the last item in a series isn’t necessary.

  • AP style: Sally, John and Rick taunted the monkeys by eating bananas in front of them.

In Chicago style, a comma before the last item in a series is required. This is the Oxford, or serial, comma.

  • Chicago style: European hedgehogs forage for slugs, beetles, and caterpillars.

I followed AP style (no Oxford comma) religiously for years, and it was usually problem-free. The key word here is usually. Take a close look at the example below to see what I mean.

  • AP style: Without the help of my clients, Eric Clapton and Margaret Atwood, I wouldn’t be here today.

See a problem? Unless the speaker’s clientele really does include Clapton and Atwood (probably not), this sentence is misleading. This is where the Oxford comma comes in.

  • Chicago style: Without the help of my clients, Eric Clapton, and Margaret Atwood, I wouldn’t be here today.

Isn’t that better? Here’s another example from collage artist Eric Edelman:


Granted, most of the confusion that stems from not using the Oxford comma can be solved by a quick rewrite, as in: “We invited Washington, Lincoln and the rhinoceri.” But I’d prefer the freedom to order my lists however I want, thank you very much.

2. No spaces around em dashes

em dash meme

In AP style, em dashes are usually formatted with spaces around them.

  • AP style: The trapeze artists — Samwell, Gladwell, and Malcolm — twirled their mustaches.

In Chicago style, em dashes are usually formatted without the spaces.

  • Chicago style: Sally reassured her mother—while crossing her fingers behind her back—that she wouldn’t go to the party.

I’ve always preferred the look of the closed-up em dashes. While others will inevitably disagree (really, it comes down to personal taste), I think it looks smoother, and makes sentences easier to read. What’s your take?

Finally, an AP style rule that I actually prefer to Chicago’s:

Not adding an apostrophe-“s after singular proper nouns ending in “s”
  • Chicago style: Socrates’s overbite was often the reason for Silas’s giggling.
  • AP style: Socrates’ overbite was often the reason for Silas’ giggling.

The way Chicago style handles this type of possessive noun will always look strange to me. That extra “s” sticks out like a sore thumb—I just can’t get used to it. What do you think?

(More info on how Chicago style and AP style treat possessives here.)

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Which way do you lean? Are there rules in your style guide of choice that aggravate you? I want to hear all about it. (Really!)

Molly McCowan
Molly McCowan is a professional writer and editor from Fort Collins, Colorado. As the Lead Word Nerd at Inkbot Editing, it's her job to make you look good.
  • Okay, call me the odd duck or call me crazy, Molly, but I like a combo of both styles. The way I see it, there’s just no one-size-fits-all. I think you might agree sometimes the choices boil down to personal preference.

    I’ll confess I’m a big fan of the Oxford Comma. 🙂

    Cool topic and very interesting read!

  • My college years (as an English major) were spent honing the rules of the AP Style. Then I came out into the wide world and saw people doing OTHER (obviously wrong) things.
    I gotta say tho, I’m with you. Have come to love the Oxford comma AND prefer no extra ‘S’ in a possessive word ending in -s.
    As for the em dash, I’m still a fan of giving them some air. 🙂 Thanks for such a fun and informative look at the two worlds of style.

  • I’m with Tea – I give my em dashes some breathing room. LOL! 😉

  • Put this in the “stuff you just sort of do without a rhyme or reason” column. I don’t like the comma, but do like the airy hyphens… but I think the extra “s” is dumb… and I bet I use way too many ellipses… completely inaccurately!

    The important thing is consistency. Use a thing or don’t use a thing. If someone reads your writing regularly and you are constantly shifting it could get confusing. Or look weird. I think a lot of that is subconscious but I think it makes a difference, especially as people get to know your style.

  • Love the spaces around the em dash, and the lack of that extra S in AP, but I’m divided on the comma. I think there are times when it makes sense to have it and times when it doesn’t matter.

    • I’m with Sharon on this. I like the extra spaces – it’s more aesthetically pleasing, in my opinion. I also do not like the extra “s” in those examples. However, I, too, am divided on the comma placement and like to keep my options open, based on the situation. Thanks for a great, thought-provoking article!

  • You had me at “Oxford comma.” <3

  • I agree with your preferences.

  • That apostrophe “s” thing always gets me – I HATE writing the extra S but never knew which was correct, grammatically. Now that I know it was a bunch of word nerds in the back of a room flipping a coin, I’m going to leave it off forever.

    That’s not the only writing rule I break, but it’s a favorite to be sure.

    The thing I’ve struggled with isn’t necessarily a rule, but that I over-hyphenate when splitting out a thought mid-sentence. Explanatory details or other a side thought added mid-stream get hyphenated and it’s always bugged me to just make it a comma.

  • The comma thing has been troubling me ever since I started blogging. Raised in the era of schooling where a misplaced comma would earn you a heavily indented red circle around said offending item and a slap across the knuckles with a splintered wooden ruler, I thought I understood commas. I don’t any more. They spill across my page like confetti and their use is no longer innate. Perhaps I got caught between the two schools and didn’t realise it. Thank you for raising this troublesome issue Molly. Back to school for me.