SMOG

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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.^{[1] [2]} The SMOG formula yields a 0.985 correlation with a standard error of 1.5159 grades with the grades of readers who had 100% comprehension of test materials.^[3]

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^[4] lacks statistical validity.

[edit] Formulas

To calculate SMOG

1. Count a number of sentences (at least: 10 from the start of a text, 10 from the middle, and 10 from the end).
2. In those sentences, count the polysyllables (words of 3 or more syllables).
3. Calculate using

   

A version is also given which is more easily used for mental math and is sometimes known as the SMOG Index:

1. Count the number of polysyllabic words, excluding proper nouns, in a sample of thirty sentences.
2. Take the square root of the nearest perfect square
3. Add 3

[edit] References

1. ^ Hedman, Amy S. (January 2008). "Using the SMOG formula to revise a health-related document". American Journal of Health Education 39 (1): 61–64. http://www.articlearchives.com/education-training/literacy-illiteracy/880189-1.html. Retrieved 2009-01-19. 
2. ^ Ley, P.; T. Florio (February 1996). "The use of readability formulas in health care". Psychology, Health & Medicine 1 (1): 7–28. doi:10.1080/13548509608400003. http://www.informaworld.com/10.1080/1354850960840000. Retrieved 2008-09-20. 
3. ^ McLaughlin, G. Harry (May 1969). "SMOG Grading — a New Readability Formula" (PDF). Journal of Reading 12 (8): 639–646. http://webpages.charter.net/ghal/SMOG_Readability_Formula_G._Harry_McLaughlin_(1969).pdf. Retrieved 2008-09-20. 
4. ^ Contreras, A.; Garcia-alonso, R.; Echenique, M.; Daye-contreras, F. (1999). "The SOL Formulas for Converting SMOG Readability Scores Between Health Education Materials Written in Spanish, English, and French". Journal of Health Communication 4 (1): 21–29. doi:10.1080/108107399127066. http://www.informaworld.com/smpp/content~content=a713851470~db=all. Retrieved 2008-09-20. 

[edit] External links

• SMOG calculator from the formula's author
• Readability Test Tool - Test all or part of a webpage by web address or referer