SMOG

SMOG (Simple Measure of Gobbledygook) is a readability formula that estimates the years of education needed to completely understand a piece of writing. SMOG is widely used, particularly for checking health messages.cite journal |last=Ley |first=P. |coauthors=T. Florio |year=1996 |month=February |title=The use of readability formulas in health care |journal=Psychology, Health & Medicine |volume=1 |issue=1 |pages=7-28 |doi=10.1080/13548509608400003 |url=http://www.informaworld.com/10.1080/1354850960840000 |accessdate=2008-09-20] The precise SMOG formula yields an outstandingly high 0.985 correlation with the grades of readers who had 100% comprehension of test materials. [ cite journal |last=McLaughlin |first=G. Harry |year=1969 |month=May |title=SMOG Grading — a New Readability Formula |journal=Journal of Reading |volume=12 |issue=8 |pages=639-646 |id= |url=http://webpages.charter.net/ghal/SMOG_Readability_Formula_G._Harry_McLaughlin_(1969).pdf |accessdate=2008-09-20]

SMOG was published by G. Harry McLaughlin in 1969 as a more accurate and more easily calculated substitute for the Gunning-Fog Index. To make calculating a text’s readability as simple as possible an approximate formula was also given — count the words of three or more syllables in three 10-sentence samples, estimate the count’s square root (from the nearest perfect square), and add 3.

Applying SMOG to other languages cite journal
author = Contreras, A.
coauthors = Garcia-alonso, R.; Echenique, M.; Daye-contreras, F.
year = 1999
title = The SOL Formulas for Converting SMOG Readability Scores Between Health Education Materials Written in Spanish, English, and French
journal = Journal of Health Communication
volume = 4
issue = 1
pages = 21-29
doi = 10.1080/108107399127066
url = http://www.informaworld.com/smpp/content~content=a713851470~db=all
accessdate=2008-09-20] lacks statistical validity.

Formulas

To calculate SMOG
#Count a number of sentences (at least: 10 from the start of a text, 10 from the middle, and 10 from the end).
#In those sentences, count the (words of 3 or more syllables).
#Calculate using
#:$mbox\{grade\}\; =\; 1.0430\; sqrt\{\; frac\{mbox\{number\; of\; polysyllables\{mbox\{number\; of\; sentences\; \}\; +\; 3.1291$

A version is also given which is more easily used for mental math and is sometimes known as the SMOG Index:
# Count the number of polysyllabic words, excluding proper nouns, in a thirty sentences.
# Take the square root of the nearest perfect square
# Add 3

References

External links

* [http://www.harrymclaughlin.com/SMOG.htm SMOG calculator] from the author