Do You Know Which Readability Test to Use for Your Document?
Although scholarly types of readers may prefer content that contains complex sentence structures with multiple syllable words that most of us would have to look up in a dictionary, writing content for the general population to read should be accomplished at a more appropriate level. In fact, reading metrics in the United States go back more than 165 years when the school systems established an individual's "Grade Level". Prior to that time, classes were taught to a collective group with much less attention paid to a student's age or level of reading proficiency. Today, writers of all sorts have an easy way of determining the reading level required for their content using differing readability tests.
One of the forefathers of readability assessment was Rudolph Flesch, an Austrian-born and naturalized American writing teacher and author. After receiving his Ph.D. in English from Columbia University, he published his most famous book, Why Johnny Can't Read: And What You Can Do About It. Flesch's early writings led to developing the early algorithms needed to measure the difficulty of content being read. About ten years later, a military officer named Peter Kincaid took Flesch's work and developed an "inversely correlated" algorithm to further determine what "level of education" would be needed to read military training manuals.
Both the Flesch reading-ease and Flesch-Kincaid grade level formulas use the relationship of words, sentences and syllables for calculating a readability score -- which in a broad sense measures clauses. By comparison, the Gunning Fog Index was developed by a businessman who was looking for a way to determine the readability of any document or correspondence. By focusing on the relationship of words, sentences and the complexity of the meaning of words, Gunning developed a formula to be used to measure the effectiveness of communication based on the reader's age. Although each method has its flaws, the problem with Gunning Fog lies in determining how complex a word really is based on the length of that word (i.e. - some short words are complex in meaning while some long words are easily understood by a child).
Today, computer-based word processing programs (i.e. - Microsoft Word) provide Flesch and Flesch-Kincaid scores as the end result of using their spell-checking program. For example, this document has a 35.9 reading-ease score and a 14.5 grade-level score, which suggests a reading level of a junior in college. Dozens of other readability engines are available online with free web-based scoring. If you go to Gunning Fog's website, you can copy-and-paste your content to receive a comparable score. In this case, a Gunning Fog score of 13.9 suggests a reading age of approximately 20 years old.
So, should I boast about my scholarly writing capabilities? Probably not. But first, let's look at the results of a recent blog article in Contently. The author sought to answer the same question about his own works only to discover that one of the best-selling books of all time, The Old Man and the Sea, was written at a 4th grade reading level. Wow.. and that's Hemingway. By comparison, our government's Affordable Care Act scored a reading level of 13.4 and Congress's Capital Budget Study a reading level of 18.2. Thus, the correctness of any writer's Readability Scores should most likely match the reading level of the content's intended audience. Unless your goal is to confuse your readers about what you have to say.