## Friday, December 28, 2012

### Another crazy metric?

I have been looking at some books about better writing since next year I am going to be giving a couple of workshops on this.
I was really intrigued that one book mentioned the Flesch Reading Ease Score which is defined by the equation:
$206.835 - 1.015 \left ( \frac{\mbox{total words}}{\mbox{total sentences}} \right ) - 84.6 \left ( \frac{\mbox{total syllables}}{\mbox{total words}} \right )$

A sign that this is a "widely accepted" metric is that it is incorporated in Microsoft Word.

The main thing that bothers me is the number of significant figures in the coefficients.

But also, surely you could devise the metric so that it actually does give values in the range 0-100, like most guides claim. Pathological text can produces negative values or values greater than 100.

#### 1 comment:

1. Hah, it looks like a joke. I agree, the decimals are ridiculous.

Surely 20* total sentences/total words + 80 * total words/total syllables works just as well. Of course, you'd never get 100, but the larger the better for ease of reading, apparently.

The number 206.835 makes me think there's an optimum length of sentence, and optimum density of syllables, which means a metric that gives ideally zero would be better. Something like

weighting_1(N_sent/N_words - optimum ratio) + weighting_2(N_words/N_sent - optimum ratio)

However, making these suggestions reminds me of this xkcd
http://xkcd.com/793/

It's interesting that shorter words is something like 5-15 times more important than shorter sentences... if I've understood correctly