Getting our numbers in line
By Doug Fisher
Recently I pulled an old sentence from my newspaper files
to illustrate a problem of subject-verb agreement. Several
readers, like Kent Ford of the Missouri Press Association,
quickly let me know it also showed another problem – poor
use of numbers.
The sentence:
Of the economists surveyed,
38 percent expect robust growth while one in five say it
is likely the numbers will not
be as good as expected.
As they pointed out, this
writer poorly mixed a percent and a ratio. This kind of
numerical sloppiness crops up
as journalists, who often say they entered the profession
to avoid numbers, find that in today’s world of statistics,
polls, studies and counter-studies, they are swimming in
numerical soup.
We can avoid this kind of
bumpiness by turning to the instinctive good sense that
we as writers have with words. We know,
for instance, that readers need common concepts and images
to which they can relate new information. And when an action
shifts, good writers firmly ground readers in the change
in time and space before proceeding.
It’s the same with numbers: We should not shift the
reader’s perspective too dramatically without helping
him or her along, or the reader is likely to leave us behind.
In the offending sentence,
the writer established the concept of percentage. Even
with a number like 38 percent that
isn’t round, readers are pretty good at using percentages
to judge that, as my grandmother used to say, “It’s
bigger than a breadbox.”
But then the writer, probably
having heard the good advice to simplify numbers when possible,
shifts to a ratio. Now
the reader has to do some quick mental calculation. The
tendency is to want to relate the new information back
to that original percentage. Let’s see, one in five
is – get out the momentary mental calculator – 20
percent.
It may take less than a
second, but it’s a speed
bump for already busy readers. Enough of those and they
may go looking for something a little less mentally taxing
over the corn flakes.
Just sticking with percentages
can become repetitively numbing. If we want to change up,
but think the exact percentage
is important, it’s helpful to relate it to a ratio.
So why not:
Of the economists surveyed,
38 percent, or about two in five, expect robust growth
while one in five says the numbers
likely will not be as good as expected.
The reader can even more
quickly grasp that the second group is half the size of
the first.
Mixing different ratios
is as jarring as mixing percentages and ratios. Let’s say that second group of economists
wasn’t 20 percent but 12.5 percent. I’ve seen
copy like this, produced, no doubt with good intentions,
by a reporter remembering that professor’s admonition
to simplify.
Of the economists surveyed,
about two in five expect robust growth while one in eight
says the numbers likely will
not be as good as expected.
That could send a reader
reaching, not for a calculator, but for the TV remote.
We might have to resort to percentages
here, but if we’re trying to convey a sense of magnitude,
not exactness, ratios still can work:
Of the economists surveyed,
about two in five expect robust growth while slightly more
than one in five say the numbers
will not be as good as expected.
Sometimes in a stylistic
flourish, a writer will keep the top number – the numerator – the same and vary
the bottom number – the denominator. There is danger:
Readers might actually perceive the larger denominator
to be the larger number.
Union leaders said that
by the end of the week one in 10 strikers would run out
of supplemental benefits and one
in five by the end of the month.
It’s better to have a common denominator, but if
the stylistic must prevail over the logical, at least provide
a clue, such as “and double to one in five.” Seeming
redundancy in the defense of understanding is no vice.
And while we’re discussing ratios, remember not to
confuse a margin with a ratio. A candidate does not win
by a 2-1 “margin,” but by a 2-1 ratio. Margin
refers to the actual difference in votes between the candidates.
New York Times public editor
Daniel Okrent, commenting on numeracy problems at The Old
Gray Lady, recently observed
that most journalists comfortable with numbers write about
sports or economics. “So it is left to the rest of
us who write for the paper to stumble through our numbers,
scatter them on the page and hope that readers understand.”
Of course, as he notes,
that’s a poor way to keep
your readers. We do that best by keeping our numbers straight.
