Which is better, one space or two after a period in a sentence?

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A trio of researchers at Skidmore College has found that text with two spaces after the period in sentences allows people to process the information they are reading faster. In their paper published in the journal Attention, Perception, and Psychophysics, Rebecca Johnson, Becky Bui and Lindsay Schmitt outline their study and what they found.

People who are old enough to have used typewriters were typically taught to insert two spaces between each sentence. This was because typewriters used monospaced fonts—without two spaces, it was sometimes difficult to see where a ended. Many of those people carried on that tradition into the computer age as they began using . But doing so has sparked some degree of debate regarding how it looks. Some suggest it is ugly, while others claim it not only looks better, but aids in reading. The debate arose because word processors typically use proportional fonts, making the need for two spaces moot. Into this great divide stepped Johnson, Bui and Schmitt. They wondered if testing whether inserting extra spaces actually improves readability might help settle things.

To test for readability, the enlisted the assistance of 60 volunteers. Each first typed up a page of text to determine if they were native one or two spacers. Afterward, each read different types of text. Some of the had double spaces after periods and commas, others had double spacing after only periods or only commas, and others yet had no extra spaces at all. As the volunteers read, the researchers used an eye tracker to see how much work was involved in the reading. The researchers also tested each volunteer for comprehension after reading.

The researchers report that the extra spaces after the period in the did appear to help the readers process what they were reading faster—their eyes did not rest as long at the ends of sentences. On the other hand, they report they found no differences in comprehension.

The researchers acknowledge that their study was limited—a small number of participants and only one font was used on all the reading material. But they suggest their findings were in line with results conducted by other researchers who have found more on a page makes for easier reading.

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Reading on electronic devices may interfere with science reading comprehension

More information: Rebecca L. Johnson et al. Are two spaces better than one? The effect of spacing following periods and commas during reading, Attention, Perception, & Psychophysics (2018). DOI: 10.3758/s13414-018-1527-6

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May 04, 2018
The same applies to quotes, exclamation and query marks, yet LitCrits and proof readers scream with outrage !!

May 04, 2018
There seems such an initiative with respect to changing even grammar and punctuation, these days. And a lot of it seems cravenly minded, from satisfying basement level "intelligences" to giving undeserving "scholars" attention they don't deserve.
Notice how often abusive nay-sayers denounce something simply based on "too long; didn't read". Proudly declaring that their drug eaten mental structure can't work with more than three sentences, the sentences no more than five words long. Common, too, people whose reactions can be said to range from catatonic to enraged when they see a comment presented as a block of text.
And note the apparently New World Order engineered insanity of the idea of putting commas ending quotations inside the quotes! The comma outside indicates the quotation is a separate element, inside the quotes would mean it is part of the sentiment of the quote.

May 04, 2018
Personally, I prefer the double-space at the end of each sentence. I read fast and I think it makes it easier to grasp the structure of what I am reading.

jpr, I am not quite understanding your comment. Are you claiming that commie comma's are an agent provocateurs for the Global Fascist Axis?

May 04, 2018
It might be though that people read it faster because they are used to double space.

May 04, 2018
The debate arose because word processors typically use proportional fonts, making the need for two spaces moot.
Except that this is utter bullshit. I tested various word processors and html text forms that I use with an image editor to measure space size down to the pixel level, and lo and behold, two spaces take up more room than a single space. Except at phys.org, naturally.

May 05, 2018
Did we pay for this nonsense?

"Rebecca Johnson
Skidmore College · Department of Psychology
· Doctor of Philosophy"


May 05, 2018

I wonder about the origin and purpose of this 'doctor of philosophy' thing...

"In the universities of Medieval Europe, study was organized in four faculties: the basic faculty of arts, and the three higher faculties of theology, medicine, and law..."

-Huh. Medicine ok, but theology and law being 'higher faculties'? Let's check the bible...

"Moreover, I saw under the sun that in the place of justice, even there was wickedness, and in the place of righteousness, even there was wickedness." Ecc3:16

- Well of course.

"early 19th century through the educational reforms in Germany, most strongly embodied in the model of the University of Berlin, founded and controlled by the Prussian government in 1810...final degree, which was labelled Doctor of Philosophy (abbreviated as Ph.D.)—originally this was just the German equivalent of the Master of Arts degree..."

May 05, 2018
- So. The 'German philosophers'.

"What enabled 19th-century culture to pursue the scientific quest and regain confidence in spiritual truth was the work of the German idealist philosophers, beginning with Immanuel Kant."

- Yeah. What German philos did in the 1800s was acquire a new credence and authority to begin establishing the great dogmas that led directly to the world wars. Nietzsche, kant, goethe, Schopenhauer, Marx et al defined the opponents and described what they were going to be fighting for.

And these definitions were based not on logic and reason but on catch phrases and buzzwords; the rest being incomprehensible gibberish.

And key to their 'argumentum ad verecundiam' was this PhD designation, a level beyond reproach.

I recommend that academia can begin to reestablish credibility by rejecting this term and it's legacy of propaganda and deception.

May 05, 2018
This article is written with single spaces. Oh the irony.

May 05, 2018
otto, you make a cogent argument. Though you did not mention among the most influential authors, either Harriet Beecher Stowe, Sun Yat-Sen or Adolph Hitler.

Now the dilemma. How do you erase all the pent up junker garbage from the curriculum without teaching it?

And do you seriously believe that the revised, purified body of knowledge you would insert, will escape being ridiculed a century or two from now?

May 05, 2018
Sorry - missed a golden opportunity, yesterday.
May the 4th still be with you....
As for double spacing - It's what I was taught and grew up with so it is kinda built into me...
But maybe that's why I use the elipsis so much...

May 06, 2018
I have discovered the same exact principle applies to writing software. Adding extra spaces and lines and making sure that there is adequate spaces around software constructs makes code much easier to read and understand. Which makes it more maintainable, and thus more valuable.

I haven't done any scientific studies to confirm this, just 40 years of experience. It certainly makes my code more easily maintainable by me.

May 06, 2018
I wonder if a better strategy could be just to start each sentence on a new line albeit at the 'cost' of 'wasting' some of the space to the left side of the pages?
I sometimes (like right here) use just that strategy when commenting on forums and I somehow think it makes what is said visually look a bit clearer.
I am writing a non-fictional science&philosophy book intended for actual publication and although I haven't made up my mind I am seriously considering using that strategy in the edit in my book;
Any opinions on that idea?
Do any of you say that's a bad idea?
Or a good one?

May 06, 2018
Surely the capital letter following a period and space would give adequate unconscious signal of the end of a sentence .personally I'd be more concerned about the trend to end a sentence with a space, not capitalise the next sentence, and place a period at the beginning.

This article is written with single spaces. Oh the irony.

It may have been written double spaced but even if it was, it will automatically be rendered single space anyway on html.

May 06, 2018
When you're reading fast enough to take a page in a few sacades, and are actually reading chunks backwards, rather than word by word, all aids to clarity are welcome. Using something like APHont is helpful, too.

May 06, 2018
hunny, personally?
It would take some adjustment on my part to accept your layout of return after each sentence.
However, I can see the possibility, that if you are expounding difficult ideas.
That slowing down the reader, preventing shallow skimming.
Might force the reader to think more about each line?
Or, ideally to ponder each point of contention.

May 07, 2018
As a long-time writer, I couldn't care less whether there is one or two spaces after a period. Like most people, I just want some fairly stable standard to cling to. I used to use two spaces; now I use one. To those who regard this as an important topic, I urge further reading...on every other topic but this one.

May 07, 2018
Not one of these comments has a double space after a period. I think it is an excellent thing to make one's sentences better understood. Would you agree with me, after reading this?

May 07, 2018
Should I make one or two spaces after a period in handwritten letters?
(The 'spaces' debate is one of those truly pointless ones)..see last panel:

May 07, 2018
Not one of these comments has a double space after a period. I think it is an excellent thing to make one's sentences better understood. Would you agree with me, after reading this?

See my post above for the reason that there are no double spaces in the comments. For example this sentence has multiple double and triple spaces.

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