Interesting Discovery

When I was in jr. high and high school I was taught to only put one space after punctuation. I was taught that putting a double space after the period was the wrong and "old" way of doing it and that now the proper way to type was a single space after periods. So that is what I've taught my students. They've all heard me say, and could probably repeat it "if you have to push the space bar more than once, you're doing something wrong!" (this was mostly to make them use the tab key instead of pushing the space bar forever, but it counts for after punctuation too). This week my students have to type a paper at home that we wrote in school. I had two parents today ask me why I was teaching their child to only single space after periods, because they believed that you were supposed to double space. This made we curious. It made me ask myself two question: Which is the correct/proper way of typing, single or double space after punctuation? Who is it that says what is correct?

I didn't find the answer to both questions, but I did find the answer to my first question. I was mostly correct. A single space is the correct way of doing it, but a double space isn't considered wrong, just old fashioned. Here's the information I found as to why:

Two Spaces After a Period--The Old Way
Here's the deal: Most typewriter fonts are what are called monospaced fonts. That means every character takes up the same amount of space. An "i" takes up as much space as an "m," for example. When using a monospaced font, where everything is the same width, it makes sense to type two spaces after a period at the end of a sentence to create a visual break. For that reason, people who learned to type on a typewriter were taught to put two spaces after a period at the end of a sentence.

One Space After a Period--The New Way
But when you're typing on a computer, most fonts are proportional fonts, which means that characters are different widths. An "i" is more narrow than an "m," for example, and putting extra space between sentences doesn't do anything to improve readability.
Notice how in this example, the "i's" and "t" take up much less space in the proportional font than they do in the monospaced font.

Although how many spaces you use is ultimately a style choice, using one space is by far the most widely accepted and logical style.
http://grammar.quickanddirtytips.com/spaces-period-end-of-sentence.aspx



With the introduction of proportional fonts in computers, double sentence spacing became obsolete. These proportional fonts now assign appropriate horizontal space to each character (including punctuation marks), and can modify kerning values to adjust spaces following terminal punctuation, so there is less need to manually increase spacing between sentences. From around 1950, single sentence spacing became standard in books, magazines and newspapers.
http://en.wikipedia.org/wiki/Sentence_spacing