Writing should reject all amplifications, digressions, and swellings of style: to return back to the primitive purity, and shortness, when men delivered so many things, almost in an equal number of words . . .a close, naked, natural way of speaking; positive expressions; clear senses; a native easiness: bringing all things as near the plainness, as they can: and preferring the language of Artizans, Countrymen, and Merchants, before that, of Wits, or Scholars.

So sayeth Thomas Sprat in 1667.  Not a literary figure but rather the historian for the Royal Society of London, a prestigious scientific institution.

One could do much worse as a call to arms for fundraising copy (setting aside the sexism of the time).   Who wouldn’t want their fundraising letter to be a close, naked, natural way of speaking?  To feel like a personal letter or conversation.  But how do we know if we’ve hit the mark?

We all use pre-checks on our writing before hitting send or print – spell check, grammar editors, human editors and last but not least, Flesch Kincaid grade level scores.

What are these grade level scores based on and do they have anything to with making your copy feel like a real letter?

Kincaid, an Army Research Institute psychologist, recommended vocabulary lists to determine readability and yet his formula doesn’t use them.  The Flesch-Kincaid evaluates readability based entirely on:

• number of syllables per word
• number of words per sentence

This gets a very easy, 4th grade score.

Dear Supporter,

We need your help. Our cause is important. Please give today. Your donation helps us. It helps people. We thank you. Please donate. We appreciate it. Thank you.

There’s two issues here,

• Any Readability Formula is a poor writing formula.  Teach to the test sucks.
• Flesch-Kincaid and other grammar formulas are the equivalent of using the scale to measure your height.

We (DonorVoice) built a Readability Score Formula by analyzing the parts of speech that occur (and don’t) at high rates in actual, personal letters and conversations.  As part of this product build we evaluated our scores in a back-test on over 80 copy samples with response rate and compared to Flesch-Kincaid scores.  The latter had low predictability and only at the extremes, 12th grade worse than 4th.    Our score was 80% accurate in predicting the higher response rate.

Building a Readability Formula grounded in the thing you’re trying to emulate is a necessary starting point.

But this doesn’t mean the formula should be considered a dictator of good writing or the basis for restricting individuality.  A formula is primarily a means of rating a piece of writing after it’s been written.

Having said that, looking under the hood of the formula is useful as a way to further familiarize oneself with what personal letters feel like.  Hunter Thompson decided to retype an existing work of fiction prior to writing his own so he knew what it felt like (he was likely wildly high at the time).

Kevin