The Scientific Case for Two Spaces After a Period (2018)
theatlantic.comI'm surprised the article did not show the difference. Here it is:
1 space after period
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I’ve written before about the effect of color gradients on reading, and how it goes against the findings of science that our words should be in a single color, usually black and usually on a near-white background, and usually presented in lines of a certain length. This is all a matter of tradition and style, not optimal information transfer. This standard does not work well for everyone. It’s why I thought, for a long time, that I didn’t like books. I wasn’t good at the mechanics of reading. When I found text-to-speech programs and actual audiobooks, it was like finally seeing the turtle in one of those Magic Eye posters that everyone else at the party saw hours ago.
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I’ve written before about the effect of color gradients on reading, and how it goes against the findings of science that our words should be in a single color, usually black and usually on a near-white background, and usually presented in lines of a certain length. This is all a matter of tradition and style, not optimal information transfer. This standard does not work well for everyone. It’s why I thought, for a long time, that I didn’t like books. I wasn’t good at the mechanics of reading. When I found text-to-speech programs and actual audiobooks, it was like finally seeing the turtle in one of those Magic Eye posters that everyone else at the party saw hours ago.
Part of the problem is that the period is overloaded. Massively overloaded. And not in a BNF (or other regular syntax) style that makes sentence breaks mechanically identifiable.
Even a period-space-capital method is far from foolproof, Mr. Anderson.
This raises an interesting consideration for typesetting engines like TeX. Maybe we should only use the full stop character for sentence breaks, and to typeset initialisms use a directive like \initials{USA}. This also allows the style/template to determine whether (or not) to intercalate the initials with full stop characters when typesetting the document.
Fwiw, I've never really liked two spaces after a period and rereading that confirms it.
To me it causes some mild confusion (if that's the right word — maybe too strong a word) with paragraph breaks. It's just too big a gap. For me it decreases readability if anything.
The dot symbol has ambiguity without extra spaces.
Mean different things. It’s rarely an issue, and not necessarily used correctly, but it is still a valuable tool.... Andrew W. Kent ... ... Andrew W. Kent ...Clearlyweshouldresurrectscriptocontnua.
Whitespace is frippery.
> I would advocate that the extra spacing should be handled at presentation time. Not as part of the content itself.
TeX/LaTeX attempts to do this, IIRC. I know there are sigils to force that one way or the other when it guesses wrong.
I'm a 2-spacer, being of a certain age and having learned to type in school on an actual typewriter. I'm also heavily invested in the Web, and I get that multiple spaces are folded into 1 on HTML. I still do 2.
I had a grudging and bitter period, decades back when writing a lot of HTML, of putting a non-breaking space after a regular space finishing a sentence, just so I could get that extra space visible. I finally folded on that one.
> I'm a 2-spacer, being of a certain age and having learned to type in school on an actual typewriter.
Yes, from posts with double-spaces I can usually tell that the author is over a certain age (I would put them at baby-boomer or near baby-boomer).
I am guilty of having been taught that way when taking Typing class in school as well.
I have since dropped it though since we no longer live in a monospace world (I know, I hear you saying, "Speak for yourself," but I am excepting coding).
I'm fine with proportionally spaced fonts when not coding. I'm also in love with extra space at the end of sentences; HTML based displays took the easy way out, there.
> Personally I think the extra space does improve readability.
In the way that I read, I find that two spaces here highlights the first word(s) of the sentence, and that makes it much slower for me to parse the meaning of the sentence as a whole.
"I've written before about", "This", "This", "It's why I thought", "I", "When I found" - usually I want to skip over these words and get to the meaning: not have them be identified as a point of focus.
I find it allows my eyes to easily find the beginning of the next sentence which allows me to read faster, since I can scan information in sentence-long chunks, then pause briefly to process the meaning before scanning the next sentence.
I'd toyed with CSS first-child, first-line, and first-letter classesva ways back ... and foud that especially for '"cards-type" formats, these made finding and distinguishing new posts far clearer.
The style is (largely) incorporated in https://old.reddit.com/r/dredmorbius. An ello example with screenshots; https://ello.co/dredmorbius/post/QGKKdiuqUw6O7ROl-V3uJA
> Personally I think the extra space does improve readability. I would advocate that the extra spacing should be handled at presentation time.
Extra space between sentences is standard in English typesetting (spacing in printed text is language-specific BTW) precisely for readability: it lets you, in general, read by sentence.
The problems with deferring it to presentation are 1 - "raw"=ish text often is the presentation (consider just long text in a code comment -- and almost anything in the terminal) and 2 - you don't always write in text that is undergoing any kind of presentation processing in realtime (e.g. you're writing TeX, or Markdown for that matter). You want to be able to read it easily.
The inverse is not a problem: a typesetting system can just coalesce spacing and make its own inter-sentence spacing decisions.
I switched to single spacing about 15 years ago when I was reading about typography for legal writing. Now I find two-spacing jarring. Also, when seeing two-spacing I somewhat irrationally get the feeling that the writer is old-fashioned or uninformed.
I understand the claim that two-spacing makes it easier to read because it separates sentences. But that is what the period does. Sentences are supposed to flow together.
Paragraphs are for separating.
And from the linked article:
“I’ve gotten a lot of flak for using a mono-spaced font (Courier New) in the study,” said Johnson.
Flak? I think using monospace font invalidates the conclusion of study.
Yes, this does need to be at presentation time. In monospace, this may make sense, but that's not how text layout works. A space is dynamically sized.
Granted, there are overloading issues, but we have had decades to refine text layout engines to account for this. Major text layout systems, including those used in publishing, need to be able to dynamically adjust spacing based upon context. Software such as InDesign does this, and it is a standard part of workflow to replace all double-spaces with single-spaces.
The extra space appears to let the sentence or thought stand on it's own. In school K-12 I was taught two spaces. College said only one.
For my district, roughly K-8 encouraged 2 spaces but changed once I got to HS. I don't know if this was an artifact of teaching us to create bibliographies and citations in MLA Style or just for ease of editing.
College and Grad School either didn't care or vehemently adhered to 1 space.
APA Style and its variants seems reasonable to me, if only for the reason that it corrects a major flaw in AP - the lack of a serial comma.
Yep, in casual text conversations (i.e. chatting with friends) I sometimes use extra spaces between words or sentences as a stylistic choice to express tone.
From a guy who learned, in high school, to set type and print pages the old fashioned way, with metal type. It was retro even back then. But what an art!
From my perspective the very concept of a typewriter-style space is an abomination wrought upon printing by the typewriter. Of course, typewriters were tremendously useful devices. I have no quarrel with them other than that.
Spaces in the retro printer world: There's this concept of the "em" or quad space. It is a square hunk of metal the same height as the letters in the typeface. We still have it in   and css rules like line-height: 1.25em;
We had five kinds of space in the lower case of the typeface. The "case" was a tray with dividers. If I remember right, they were
-- em (quad)  
-- en (half a quad)  
-- thick ( ~ 1/4 of a quad) the ordinary space and in most fonts.
-- middle ( ~ 1/5 of a quad)  
-- thin ( ~ 1/6 of a quad in most typefaces)
-- numberspace (the same width as the numerals in the typeface, an early nod to <pre> for tables.
Notice that the precise widths of the thicks, middles, and thins are determined by the typeface's designer. Then and now.
Our teacher told us to set up body copy with thicks between words.
We then justified each line manually by putting two thins in place of a middle to add space, or one thin to remove space. Choosing where to adjust the space was an art. It was good to avoid rivers of space running down the page. (Adobe InDesign gives enough control to do this; I don't think other programs do.)
AFTER SENTENCES, we used ens for most copy, and ems for poetry and that sort of thing. I am pretty sure the two-space typewriter convention grew out of printers' ens or ems after sentences.
In the 21st century digital typefaces have contextual glyphs. That makes it easy for the FONT DESIGNER to choose the default spacing between sentences. That's as it should be. The rest of us should pass dot space to the font. The font designer "owns" legibility.
I, for one, have had a heck of a time unlearning the dot space space sequence I learned in high-school typing class.
monospace source text: two spaces.
WYSIWYG or compiled final output: the layout engine knows how to adjust keming better than i do, and will strip out or adjust space distances to look “right” no matter how many spaces I type. So i might as well type two and maintain hand memory consistency.
So as far as i’m concerned, it’s a no-op in practice. For myself i learned two-space long ago, my hands are unlikely to retrain themselves to type otherwise, and it’s probably a slight legibility help in docstrings and latex source.
edit: as i edit this on my phone i realize that one place this doesn’t work is on an on-screen keyboard. There, typing the second space too quickly usually inserts another period!
Somewhat amused by the "keming" you refer to. I assume it's tongue-in-cheek. :-)
Double-space into period is a customizable feature of on-screen keyboards (at least Gboard).
yea that was an intentional typo :)
There is a decent-sized subreddit called Keming[0], if anyone's interested.
Several years ago I started putting every sentence on a new line when I write LaTeX, as it makes diffs cleaner if I want to go back and compare versions of a document.
I do the same but I noticed it feels very weird to write like that, it feels much more staccato, as if there's a bigger pause between each sentence. Nowadays I write paragraphs normally and then split the lines afterwards.
For the most part I do the same when writing emails.
Appears to be a higher chance of people reading them that way.
I don't write a lot of fluff though, and usually have two or three trimming passes before sending.
we’re all conditioned by twitter now, it should be fine! /s
Now that you mention it though i bet there’s an easy macro to do this in emacs ...
I do the same in source documentation, to limit the portion that has to be reformatted when changing something in the middle.
i’d have trouble keeping line length limits in docstrings.
It doesn't mean that a sentence can't contain line breaks. It means that there's a line break after each sentence. This causes paragraph reformatting (for maintaining line length) to be restricted to the current sentence, instead of also affecting the following sentences.
For me two spaces in fixed-width fonts is too jarring, as the spaces themselves are significantly wider than in proportional fonts (relative to average letter width), and also the period glyph already adds horizontal space.
For proportional fonts, on the other hand, two spaces would help the layout engine to distinguish between the end of a sentence and other uses of period-followed-by-space (abbreviations, mostly).
Two spaces should be a good rule for plain text formats, like Markdown or reStructuredText -- this way the parser can identify sentences and recognize the punctuation that ends an abbreviation vs the one that ends a sentence. (It's not that any parser is doing this currently, as far as I know.)
How would you handle the case in which a sentence ends with an abbreviation?
You cannot get everything :) It will recognize this as the end of a sentence. One use case I was thinking of was to automatically make spaces after initials non-breaking, as in "R. P. McMurphy".
Two spaces distinguish sentences.
The abbreviation ends a sentence. It gets two spaces.
Not that civilization would settle on such a thing to a degree where this would be dependable, but it would certainly help machine processing of text to understand that the two spaces indicates a new sentence, while some abbreviation with a period in it, then a space, does not represent the last word in a sentence.
I still use two spaces at the end of a sentence in text messages. Pry them from my cold dead thumbs, etc.
Two spaces, like the Oxford Comma, reduce ambiguity and aid in visually parsing text information.
As a side benefit, that extra space can help software identify a sentence vs a line which contains something like Mr. Bob. With a two-space system, Mr. Bob would be part of one sentence. In a one-space system, the software cannot tell if the sentence ends at Mr. with the next sentence beginning as "Bob ..."
Is this just an American thing? I was educated in the UK and it never once came up (we use a single space), nor have I heard of it anywhere except online conversations with Americans.
It is not, also educated in the UK and two spaces were required. HTML makes it hard to double space, and we get a lot of reading material via the web now, so maybe this is why single space is the world standard.
It is harder to read, but other aspects contribute here too (overly wide or narrow columns, bad contrast, bad font choice, late-bound style/fonts/js/ads that move what you're reading, dancing hamsters)
interesting! where were you educated (mine was private school, gen X, SW England)? Is this a class thing, or a regional thing, or a generational thing, or what?
State - SW England & Catholic - NE Scotland. I'm not sure? But I first started (outside of school) on a typewriter, and terminals were all fixed width (Acorn, Amiga, BBC) - which the argument goes is where it came from (although the typesetting comment by @OliverJones suggests otherwise).
I wonder if perhaps it was just a function of the teacher you had? The world was less connected (even now parts of education are individual preferences rather than rules). Oxford comma, punctuation inside or outside brackets, etc vs et cetra vs &ct
I had an Acorn Atom (still have it, though I can't get it working any more). Nothing in there suggested 2 spaces after a full stop ;) And the manual used to talk about the "computer programme"!
I guess it's down to teacher and style, as you say. I find it interesting that I never met this until post 2000 internet forums with Americans, though. I wonder how widespread it is.
And like tabs vs spaces, I get that there's a "this is the way" answer. Tabs are the right answer, and anyone who says spaces is an idiot. But 2 spaces after a full stop is clearly the right way, but I'm buggered if I can bring myself to do that ;)
The only time I got told to use two spaces was by my dad. Literally everywhere else, it was single space. In school, two spaces was considered bad grammar and would get marked in red ink.
I'm not sure about it being restricted to americans, but yes, that is how I was taught in public schools. I'm from the U.S.
I've come across it in the UK. I remember a friend's mother, born in ~1940, insisting on it.
Vim's default behavior is to put two spaces after a period when reformatting (for example with gq).
If you prefer to keep one space instead of two you can use:
set nojoinspaces"The two-space convention is left over from the days of typewriters."
And that convention itself came about as an imitation of common 19th-century typesetting style, where more space after punctuation was still fairly normal. Technological and aesthetic changes--the adoption of Monotype and Linotype machines, and the influence of early book designers like Bruce Rogers--started a trend to more even spacing in typeset printed books.
Im not convinced that the two spaces thing is a typesetting artifact. If you look at the declaration of independence and the constitution, which weren't typeset, there are larger spaces between sentences than words.
I'm with HTML: screw how many spaces you want to pollute your words with, I'm replacing them all with a single space.
Random facts. French puts a half-space before any punctuation mark with two parts:
https://crowdagger.github.io/textes/articles/heuristique.htm...
Although in Quebec they only do it before colons:
https://www.btb.termiumplus.gc.ca/tcdnstyl-chap?lang=eng&let...
German used to put spaces before punctuation, now doesn't, and some guy on Usenet came up with a term for it:
FranklyIprefertheancienttraditionofusingneitherpunctuationnorspacesCapitalizationisoptional
I+personally+quite+like+the+word+dividers+used+in+runes.
Don't forget the .nodehportsuob
Emacs has forward/backward-sentence (alt-e/alt-a) commands, but you have to have two spaces after a period for it to know where sentences begin/end.
Let the bike shedding begin.