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.)

*    *    *

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.