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= |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= |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 =
] lacks statistical validity.


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


External links

* [ SMOG calculator] from the author

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • smog — smog …   Dictionnaire des rimes

  • Smog — is a kind of air pollution; the word smog is a portmanteau of smoke and fog. Classic smog results from large amounts of coal burning in an area caused by a mixture of smoke and sulfur dioxide. Modern smog does not usually come from coal but from… …   Wikipedia

  • smog — s.n. Ceaţă deasă, amestecată cu fum şi cu praf industrial, formată în regiunile industrializate sau în marile oraşe, cu efecte dăunătoare asupra sănătăţii populaţiei. – Din engl. smog. Trimis de RACAI, 07.12.2003. Sursa: DEX 98  smog s. n.… …   Dicționar Român

  • smog — [ smɔg ] n. m. • 1905; mot angl., de smoke « fumée » et fog « brouillard » ♦ Anglic. Brouillard épais formé de particules de suie et de gouttes d eau, dans les régions humides et industrielles. ● smog nom masculin (anglais smog, de smoke, fumée,… …   Encyclopédie Universelle

  • Smog — Sm erw. fach. (20. Jh.) Entlehnung. Entlehnt aus ne. smog, einer Kreuzung aus ne. smoke Rauch und ne. fog Dunst, Nebel .    Ebenso nndl. smog, ne. smog, nschw. smog, nnorw. smog; Smoking. ✎ DF 4 (1978), 241f.; Rey Debove/Gagnon (1988), 934;… …   Etymologisches Wörterbuch der deutschen sprache

  • smog — smòg s.m.inv. CO coltre di nebbia densa e scura costituita da vapore acqueo misto a fumi e altri residui di combustione, che ristagna spec. sui grandi centri urbani o industriali: lo smog inquina l aria delle grandi città, prendere provvedimenti… …   Dizionario italiano

  • smog — smog·gy; an·ti·smog; smog·less; smog; …   English syllables

  • smog — smȍg m DEFINICIJA ekol. 1. magla s visokim stupnjem onečišćenja od industrijskih emisija i automobilskih ispušnih plinova 2. meton. zagađenje zraka proizvodima izgaranja SINTAGMA fotokemijski smog smog koji je nastao oksidacijom hidrougljika,… …   Hrvatski jezični portal

  • smog|gy — «SMOG ee», adjective, gi|er, gi|est. full of smog: »There was a virus in the…smoky, smoggy air (Newsweek) …   Useful english dictionary

  • Smog — der; [s], s <aus gleichbed. engl. smog, zusammengezogen aus smoke »Rauch« u. fog »Nebel«> dicke, undurchdringliche, aus Rauch u. Schmutz bestehende Dunstglocke über Industriestädten …   Das große Fremdwörterbuch

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.