SMOG Index

From Wikipedia, the free encyclopedia

The SMOG Index is the approximate version of SMOG (Simple Measure Of Gobbledygook), making this readability test easy to calculate manually. SMOG can be calculated more accurately with the instant free online SMOG Calculator which uses the precise formula that yields a correlation of 0.985 with the grades of readers who had 100% comprehension of test materials. No other readability formula is believed to correlate so highly with its criterion.

[edit] Formula

  1. Count the polysyllabic words (of 3 or more syllables) in 3 10-sentence samples from a text
  2. Estimate the square root from the nearest perfect square
  3. Add 3

The result estimates the number of years of U.S. education needed to fully comprehend the text.

The precise SMOG formula generalised for more than 30 sentences is

1.0430 \sqrt{total\ complex\ words \times \left ( \frac{30}{total\ sentences} \right )} \ + 3.1291

SMOG is mainly used by bodies such as the National Institutes of Health to gauge the comprehensibility of information for the public. First published in G. Harry McLaughlin (1969) SMOG grading: A new readability formula. Journal of Reading, 12 (8) 639-646,[1] SMOG has always been in the public domain.

[edit] External links