The book that I’m currently reading is chock-full of some of my biggest typographical pet peeves.

Am I the only person who  notices when an extra space is used inadvertently between two words of a sentence? Even the grammar checker in Microsoft Word is kind enough to let you know when you make this mistake. It really drives me crazy; I seem to find doubled spaces everywhere I look. (Did you notice the doubled space in the first sentence of this paragraph?)

Speaking of doubled spaces, please don’t type two spaces after the closing period of a sentence. The Elements of Typographic Style (and Bill Hill!) back me up on this one. I know that your typing teacher told you to use two spaces. I don’t doubt that typing teachers are still teaching two spaces, but that doesn’t change the fact that it’s wrong. (Don’t use two spaces after a colon, either.)

One more – when typesetting source code with a fixed-width font, please don’t use ligatures. (Notice the “fi” – that should be fixed-width font.) I don’t understand why any fixed-width font would support ligatures anyway – doesn’t that violate the idea of letters being a fixed width? Of course, the easiest way around this problem is to stop using fixed-width fonts for source code – it reads a lot better in a normal font, anyway. On screen, 10pt Verdana is the best font for reading and editing source code that I’ve found; I’m sure a similar font would look great in print.

Update: David (a coworker) reminds me that there are books in print that use variable-width fonts for source code, most notably The C++ Programming Language (3rd Edition) by Bjarne Stroustrup, which uses an italic roman font, and Effective C++ (3rd Edition) by Scott Meyers, which uses a sans-serif font like Verdana. I found both to be more readable than the standard fixed-width Courier, particularly the latter.

Update 2: Speaking of source code, don't let your word processor or typesetting software make any helpful character substitutions. For example, I don't know of any programming languages that allow “smart quotes” around "string literals".

Update 3: Al prefers double spaces after full stops and colons, and asked that I quote the relevant passage from The Elements of Typographic Style:

2.1.4  Use a single word space between sentences.

In the nineteenth century, which was a dark and inflationary age in typography and type design, many compositors were encouraged to stuff extra space between sentences. Generations of twentieth-century typists were then taught to do the same, by hitting the spacebar twice after every period. Your typing as well as your typesetting will benefit from unlearning this quaint Victorian habit. As a general rule, no more than a single space is required after a period, a colon or any other mark of punctuation. [...]

As you may have noticed, I'm in the midst of a serious blogging lull. On the business front, we're pushing hard to ship the next version of our flagship product; on a personal front, I'm in the complex process of buying a new home, selling an old one, and moving all of our stuff from one to the other, not to mention wrapping up loose ends with the people and places we're leaving behind. We've got a busy summer ahead as well, but I do hope to get back into the blogging pattern again soon. I've still got books to review and plenty of JavaScript stuff to talk about...

Most of my readers already have Gmail accounts, I'm sure, but if you don't, and you'd like one, just drop me a note and I'll send one your way.

I’m definitely not happy with my definition of “100% shorter” from last time. After all, if “100% longer” means “twice as long”, shouldn’t “100% shorter” mean “twice as short,” which is “half as long”?

To figure this out, let’s use “inverse-inches.” So if our rope is 60 inches long, it is 1/60 inverse-inches short. “100% shorter” is thus 1/60 + 1/60 = 1/30 inverse-inches short, or 30 inches long:

• 50% shorter – 1/60 + 1/120 = 3/120 inverse-inches – 40 inches
• 25% shorter – 1/60 + 1/240 = 5/240 inverse-inches – 48 inches
• 75% shorter – 1/60 + 3/240 = 7/240 inverse-inches – 34.3 inches
• 200% shorter – 1/60 + 2/60 = 3/60 inverse-inches – 20 inches
• 300% shorter – 1/60 + 3/60 = 4/60 inverse-inches – 15 inches

Now “200% shorter” is the same as “three times as short” (as described last time), which works the same way as longer/long, so I think we’ve got it. Still, it’s not exactly obvious.

In any case, length is obviously not the only measurement that this applies to; some of these seem more sensible than others:

• half as young is twice as old; twice as young is half as old
• half as many is twice as few; twice as few is half as many
• half as wide is twice as narrow; twice as narrow is half as wide
• half as big is twice as small; twice as small is half as big

(Of course, “big” has its own problems – what’s “twice as big” as a 13-inch television? Shall we double the lengths of the sides, the length of the 13-inch diagonal, the area of the screen, or the volume of the box? We’d need to be more precise.)

This stuff actually makes more sense when we use ratio measurements, as with our original measurement of speed. We measure how fast something is by measuring how many tasks are accomplished in an amount of time, e.g. miles per hour – bigger numbers are faster. To measure how slow something is, we measure the inverse, which is how much time it takes to do a number of tasks, e.g. seconds per lap – bigger numbers are slower.

So, if my task took 20% less time, then a previously 100-second task would now take 80 seconds. To measure how fast the task is, we invert the measurement – I improved the speed from 1/100 tasks per second to 1/80 tasks per second. In decimal, that’s 0.01 tasks per second to 0.0125 tasks per second. That’s an improvement of 0.0025 tasks per second, which is 25% of 0.01, so we’d say that the task runs 25% faster.

Ouch. My brain hurts. Since I’d have to justify why shaving 20 seconds off of 100 is “25% faster”, I should probably stick with “20% less time.”

In summary then, we should probably avoid using phrases that would require us to invert our preferred form of measurement. Even “150% longer” can be confusing (it means 2.5 times the length), so you might avoid phrases like that as well. Stick with language that is clear and unambiguous.

I had just optimized some code, and was about to say that it was “20% faster” when I realized I wasn’t really sure of what that meant. I said “takes 20% less time” instead, but now I have to know – what is “20% faster”?

(This may seem silly, but there’s a practical side as well. You find these kinds of measurements all over the place, particularly in product marketing. Just Google some of these phrases and see for yourself.)

Let’s start with something that seems obvious: length. If our old rope is 60 inches long, this is how long the new rope would be, depending on how we describe it:

• as long – 60 inches
• twice as long – 120 inches
• half as long – 30 inches
• three times as long – 180 inches
• one-third as long – 20 inches

Makes sense, right? What if we use the word “longer” instead of “as long”? That is, how long would the string be if it was “200% longer”? Twice as long, i.e., 120 inches? That seems reasonable, until you consider what “50% longer” would mean:

• 50% longer – 1.5 times as long – 90 inches
• 100% longer – twice as long – 120 inches
• 200% longer – three times as long – 180 inches

Let’s make things a little more complicated. What about the word “short”? How long would the string be if it was “half as short”? That’s a tough one. Many people would use that phrase if they thought that the old rope was “short” already, and they would mean that it was “half as long,” i.e., 30 inches. But what if we said it was “twice as short”? That’s got to be “half as long,” too.

The difficulty here is that we don’t have a number that gets bigger as the rope gets shorter. The only logical thing to do is to make “short” the inverse of “long”:

• as short – as long – 60 inches
• twice as short – half as long – 30 inches
• half as short – twice as long – 120 inches
• three times as short – one-third as long – 20 inches
• one-third as short – three times as long – 180 inches

Those figures just seem weird, so it would probably be best to avoid that usage. Of course, we wouldn’t be done unless we considered “shorter.” How long would the new string be if it was “50% shorter”? We’d better just subtract that percentage from the original length:

• 50% shorter – 30 inches
• 25% shorter – 45 inches
• 75% shorter – 15 inches

By that logic, “100% shorter” wouldn’t make much sense, since it would be 0 inches. “200% shorter” makes even less sense. Again, you probably want to avoid using “short” or “shorter” when describing relative measurements.

Well, that’s all for now. Tune in next time for the next exciting installment of “Relative Measurements in English,” where we’ll discuss other forms of measurement, and finally decide what “20% faster” really means!