by Daily Writing Tips
Variety of sentence length is an important factor in good writing — attending
to the number of words in each sentence enhances the rhythm of your composition
— but careful writers occasionally monitor average sentence length, too.
There’s no reason to obsess about either factor, but check your numbers now
and then. Although variety of sentence length occurs naturally, it’s a good
idea, when it’s feasible, to recite your writing aloud to ensure that stacks of
sentences of repetitively equal or nearly equal length aren’t slipping through.
Note, however, that though striving for variety of length and attending to
average length may seem contradictory practices, average length has nothing to
do with consistent length.
And what’s the ideal average sentence length? It depends on the formality of
your writing, and on your writing audience. Roughly, for a general audience, an
ASL of less than 15 words is considered easy, 15 to 20 words is moderate, and
more than 20 words is difficult.
I measured my posts from last week and discovered that they ranged in ASL
score from 20.7 words to 33.9; the others were spaced fairly evenly within this
range. I frequently employ colons to signal additional statements, and I didn’t
count what follows the colons as separate sentences, but even if I did, the ASL
for most of my posts would still likely be in the 20s. However, as I noted in my
post about reading
level, I assume that many Daily Writing Tips readers are above the norm in
reading comprehension (though a sizeable number are English-language
When I read about a study of ASL published in 1985, I learned that the ASL
figures for leading American newspapers and magazines are comparable to the
numbers for my posts. (Or they were comparable: The ASL for the best periodicals
has probably declined in the last quarter-century.) But if I were writing for
more modest general-interest publications, I would make an effort to reduce ASL
to the low 20s or even the high teens.
Here’s a more complicated index called the fog factor: After determining the
ASL, divide the number of words of three or more syllables by the total number
of words. Add that number to the ASL. Multiply the sum by 0.4.
The number corresponds to reading-comprehension level corresponding to the
number of years of education. For general-interest publications, the ideal total
is between 7 and 9. The total for this post is over 14. Again, considering that
it’s published on a blog about writing, that’s not excessive. However, if it
inched any higher, or if the ASLs for my posts were routinely hitting in the
upper 20s, I’d strive to simplify.
Clarity, construction, and correctness are the most important elements of
good writing, of course, but conciseness is also a virtue.