The hyphen is the key on your keyboard. It's what goes between some words when they're acting as one word, e.g. mother-in-law.
The dash is longer--it's either a long ("em") dash character or 2 hyphens, as I used here--and it's the grammatical construct that acts somewhat like a comma.
And I'm not just nit-picking. It's confusing to use a hyphen when you mean dash, especially when you also have hyphens in the vicinity. Here's the sentence that convinced me to post this:
>I predict a complete heads-up match with
Facebook–Zynga’s now been double-crossed not once but twice by
Zuckerberg.
The characters in "heads-up" and "double-crossed" are both hyphens, but the character between "Facebook" and "Zynga" should be a dash (or 2 hyphens).
Edit: So he's using en dashes, which are shorter, but they are different from--and slightly longer than--hyphens. But it's much easier to tell an em dash from a hyphen than an en dash from a hyphen, and the em dash is proper.
Here's a hyphen, followed by an en dash, followed by an em dash:
Were you actually confused? Are you smart enough to know what an "em" dash is and not smart enough to know that the hyphen in heads-up works differently than Facebook-Zynga. The only way that would make sense is if they merged and for some reason kept Zynga as part of their name. Given the context that's obviously not happening.
An em dash is typically considered bad practice in formal writing. If he wanted to be formal he would have used a semicolon I think. In informal writing an em dash often replaces the work of other punctuation.
Note: I don't care. I was able to understand him just fine and that's all I care about. If he was writing a scholarly paper I'd take the time to correct it and send him some suggestions. I'd also only do this if I was asked to do so.
Was I able to figure it out? Sure. But did I have to pause for a second to figure out what he was saying? Yes.
Proper punctuation makes it much easier for readers to read and comprehend the material quickly. If you don't believe me, try reading a paragraph with no punctuation at all. You'll spend most of your time trying to figure out what words are grouped together because there's no punctuation to clue you in.
I think it's better done with spacing, as in "to-day - a good day - is the middle of the week", when you're not being anal enough to use &emdash; or Unicode literals etc.
I think the non-spaced -- looks a lot like double-spacing after full stops (periods): quite old-fashioned. Reminds me of books from the 50s I read in the 80s.
Many of these typographical conventions are fashion and culture based, anyhow. Quotation marks are especially diverse, with the << >> in French, the em-dashes used by Joyce, etc.
Hm, you're right. They look basically identical on his blog, but different here. And now that I look really closely, they appear to be slightly longer on his blog as well.
Edit: Also, it's a lot easier to tell in Firefox 3 than Chromium. Ah, the web.
The hyphen is the key on your keyboard. It's what goes between some words when they're acting as one word, e.g. mother-in-law.
The dash is longer--it's either a long ("em") dash character or 2 hyphens, as I used here--and it's the grammatical construct that acts somewhat like a comma.
And I'm not just nit-picking. It's confusing to use a hyphen when you mean dash, especially when you also have hyphens in the vicinity. Here's the sentence that convinced me to post this:
>I predict a complete heads-up match with Facebook–Zynga’s now been double-crossed not once but twice by Zuckerberg.
The characters in "heads-up" and "double-crossed" are both hyphens, but the character between "Facebook" and "Zynga" should be a dash (or 2 hyphens).
Edit: So he's using en dashes, which are shorter, but they are different from--and slightly longer than--hyphens. But it's much easier to tell an em dash from a hyphen than an en dash from a hyphen, and the em dash is proper.
Here's a hyphen, followed by an en dash, followed by an em dash:
-
–
—