Are Two Spaces Better Than One?

What better way to start out your Monday morning than a debate on the number of spaces to put after a period?  On Friday, May 4, the Washington Post published a story about a recent study that found that putting two spaces after a period improves readability.  The study, conducted by psychology researches at Skidmore College, had 60 students type a paragraph read to dictated to them.  Of the 60 students, 21 put two spaces after the period.  The researches then had the students read some paragraphs and used eye-tracking software and comprehension questions to test readability. 

The study concluded that the two spaces, according to the Washington Post, made "reading slightly easier."  But as the Post story and another article by typography expert Matthew Butterick point out, the answer really isn't that simple.  First, the only people who showed improvement were those who originally typed with two spaces after the period, and the improvement was pretty slight.  Second, Butterick notes that the improvement was only in reading speed and not in reading comprehension.  Third, the experiments were conducted using Courier New font, which is a fixed-width font that is very different from the modern variable-width fonts used more commonly today on computers.  Butterick points out a few other faults in his article, including the fact that the paragraphs the students had to read were rather short.

As readers of this blog can tell, I am fiercely loyal to the two spaces approach (and the Oxford comma, but that is another story).  While I would love to make some argument about readability, for me it is just force of habit.  Those two clicks of the thumb on the space bar are just second nature.  As we move into more and more electronic reading, I do wonder if the spaces provide a little break for the eye or an informal mind cue that that a sentence is ending.  So, I will keep my double spaces (and publishers and law reviews will continue to remove them).