Period

At my job, the first thing I do when I edit is formatting. Concentrating on the look of the article first standardizes its appearance and removes distraction, making it easier to then concentrate on the content. If the author has skipped two spaces after a period, the first thing I do with that article is delete one space after every period, like a factory worker picking out imperfections on an assembly line.

There is a study in Attention, Perception and Psychophysics noting that leaving two spaces after a period helps with reading comprehension, allowing the eye to move faster over text, but I’m not buying it. It should be one space after a period. The new study may have attacked this question from a scientific viewpoint but I will argue it from an aesthetic viewpoint. Leaving two spaces just looks ugly. When I see two spaces, it just looks distracting to me, like holes in a T-shirt.

The whole reason people used two spaces in the first place was because of typewriters. With typewriters, each letter fit in a slot of equal size. Since “w” took up all that slot, there was less space around it than the slot around the letter “l.” The spaces around letters were uneven by default, so two spaces after a period stood out and let people know that was the end of the sentence. I think this is why so many people use two spaces: they learned on typewriters or learned from someone who learned on typewriters. It’s a style that seems as outdated to me as using a slide rule. In proportional fonts, which we’ve had for the last 40 years or so, we don’t have that problem, since the letters bump right up against one another. So we don’t need that extra space.

The study notes that reading comprehension was not affected by punctuation spacing but participants’ eye movement suggested that two spaces after a period facilitated their initial processing of the text. The effect in the study seems small to me, and it’s not as if having one space after a period has a huge negative effect on reading comprehension or speed, so why use two spaces if they look ugly on the page?

There is a big flaw in this study in that researchers used Courier New, a typewriter font that was designed for two spaces after a period, so of course two spaces would be more helpful. But few people outside the government use this font, so I think it would be fairer to conduct a test in a modern font. Amusingly, the online and PDF versions of the study used one space after every period.

Keep in mind that this is just one study in favor of two spaces after a period. On the other side, we have people like me, who have worked for over 20 years in publishing and know what is readable on the page. We also have publishers, the great majority of which have decided one space after a period is the way to go. Find a professionally published book or magazine or something online that uses two spaces after a period. Outside of the government (which uses typewriter fonts) and some academic materials, you won’t find much.

There must be a reason for that and I think the fact that an overwhelming majority of professionally published materials use one space after a period should overrule what people learned in keyboarding class in 1990 and overrule the results of one study. 

By the way, if you read anything about this study and the headline is some variation of “Science proves it,” it means the author has no idea how to write about a scientific study.