SMOG (Simple Measure of Gobbledygook)'s a readability formula that estimates the years of education needed to completely understand a piece of writing. SMOG's widely used, particularly for checking health messages. The SMOG formula yields a 0.985 correlation with a standard error of 1.5159 grades with the grades of readers who'd 100% comprehension of test materials. SMOG was published by G. Harry McLaughlin in 1969 as a more accurate and more easily calculated substitute for the Gunning-Fog Ind… (More on Smog)