From Wikipedia, the free encyclopedia
Measure of readability
The
SMOG grade
is a measure of
readability
that estimates the years of education needed to understand a piece of writing. SMOG is an acronym for "Simple Measure of Gobbledygook".
SMOG is widely used, particularly for checking health messages.
[1]
[2]
The SMOG grade 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]
The formula for calculating the SMOG grade was developed by G. Harry McLaughlin as a more accurate and more easily calculated substitute for the
Gunning fog index
and published in 1969. 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.
A 2010 study published in the
Journal of the Royal College of Physicians of Edinburgh
stated that “SMOG should be the preferred measure of readability when evaluating consumer-oriented healthcare material.” The study found that “The
Flesch-Kincaid formula
significantly underestimated reading difficulty compared with the gold standard SMOG formula.”
[4]
Applying SMOG to other languages lacks statistical validity.
[5]
Formulae
[
edit
]
To calculate SMOG Index
- Take three ten-sentence-long samples from the text in question.
- In those sentences, count the
polysyllables
(words of 3 or more syllables).
- Calculate using
This version (sometimes called the SMOG Index) is more easily used for
mental math
:
- Count the number of polysyllabic words in three samples of ten sentences each.
- Take the square root of the nearest
perfect square
- Add 3
SMOG conversion tables compiled by Harold C. McGraw are slightly inaccurate because they are based on the approximate formula. Furthermore, tables for texts of fewer than 30 sentences are statistically invalid, because the formula was normed on 30-sentence samples.
References
[
edit
]
- ^
Hedman, Amy S. (January 2008).
"Using the SMOG formula to revise a health-related document"
.
American Journal of Health Education
.
39
(1): 61?64.
doi
:
10.1080/19325037.2008.10599016
.
S2CID
72389214
. Retrieved
2009-01-19
.
- ^
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
.
- ^
McLaughlin, G. Harry (May 1969).
"SMOG Grading ? a New Readability Formula"
(PDF)
.
Journal of Reading
.
12
(8): 639?646
. Retrieved
2018-04-26
.
- ^
Fitzsimmons,P.; Michael, B.; Hulley, J.; Scott, G. (2010).
"A readability assessment of online Parkinson's disease information"
.
J R Coll Physicians Edinb
.
40
(4): 292?6.
doi
:
10.4997/JRCPE.2010.401
.
PMID
21132132
.
- ^
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
.
PMID
10977275
.