Republished from the May 7th 2018 Newsletter.
There was a study floating around this past week about how using two periods after spaces was actually correct because they did a Science about it. Unfortunately, the study was about some specific circumstances where it might be true and then the “reporting” morphed that into “Always use two now!”
“Most notably, the test subjects read paragraphs in Courier New, a fixed-width font similar to the old typewriters, and rarely used on modern computers.”
Practicaltypography.com has a great overview of all the other issues with drawing some vast conclusion on who is RIGHT forever and ever from this study:
“True, the researchers found that putting two spaces after a period delivered a “small” but “statistically … detectable” improvement in reading speed—about 3%—but curiously, only for those readers who already type with two spaces. For habitual one-spacers, there was no benefit at all.”
I agree with them that studies like this are important to do. They often don’t surface new information that typographers don’t already know, but sometimes they do!
More broadly: typography should always be about legibility first. Once that it satisfied we can have a number of fun discussions and arguments about the design of it. It’s gotta be readable though. I personally think that modern variable width fonts are very good at handling spacing issues automatically for you though.