21% of U.S. adults have trouble using a street map
If you’re writing for a broad audience, you might consider starting with eighth on the Flesch-Kincaid test. Ratchet up or down from there depending on your audience members’ sophistication.
Why so low?
In 1993, the U.S. Department of Education conducted the first National Adult Literacy Survey (NALS), the most comprehensive, statistically reliable source on literacy in the United States. It studied 26,000 U.S. adults, representing 191 million people.
Three literacy scales. The study looked at:
- Prose literacy — the ability to search, understand and use information from linear copy, like articles.
- Document literacy — the ability to search, understand and use information from nonlinear materials, like maps.
- Quantitative literacy — the ability to identify and perform computations using numbers from printed material.
The results? Nearly half of the Americans surveyed weren’t literate enough to read a sports article and identify the age at which the swimmer began swimming competitively, according to “Adult Literacy in America” (pdf), a report based on that study.
Percentage of U.S. adults who can read at different estimated grade levels,
according to the 1993 National Adult Literacy Survey (NALS)
Since 1847, scholars and others have been measuring how hard copy is to read. Over the years, these folks have created some 200 readability indexes — from the Flesch to the Fry, from the Fog to the SMOG, from the Spache to the LIX.
All of these indexes boil readability down to a mathematical formula. Those formulas usually comprise two factors:
- Sentence length. This measures “syntactic,” or structural, difficulty. Most formulas measure the average number of words per sentence.
- Word length. This measures “semantic,” or meaning, difficulty. Most formulas measure the average number of syllables or characters per word.
One way to measure your copy’s readability is to use STORYtoolz readability statistics. Just enter your message, and STORYtoolz will run it through seven popular indexes. You’ll find out all kinds of fascinating details about your piece, from the number of characters per word to how often you use the passive voice.
To improve your reading grade level, just reduce the length of your sentences and words. Your readers will be glad you did.
Worried about talking down to your audience? Don’t. Most audience members — even brain surgeons and rocket scientists — are tired, busy and overwhelmed with information. They’ll be happy to get your copy in a more digestible package.
Keep in mind that the front page of The Wall Street Journal is written at the ninth-grade level. This piece, which I wrote for a highly literate audience — you! — weighs in at the eighth grade reading level, according to Flesch-Kincaid.
How much harder would you like it to be?