TO: Faculty
FROM: Al Atkinson, David Barnett, Sandra Carpenter, Reading Consultants
RE: Readability of Textbooks

Last fall, we printed a readability formula for use in determining the difficulty of
your textbooks. Since at this time of year, you may be examining new textbooks for
use in the fall, we have decided to reprint the formaula.

SMOG Grading Formula (simplified)

Count off 10 sentences at the beginning, 10 in the middle and 10 at the
end of an article.

2. Count every word of 3 or more syllables in your 30 sentences.

3. Estimate the square root of the sum of your big words.

4. Add 3 to the square root.

This equals the grade level.

In addition, you may want to consider one of Rudolph Flesch's reference charts for
determining difficulty of material.

Words in Number of Typical Estimated Percent

Average Syllables Magazine Grade Ohaus @
Sentence per 100 wrds. Level Adults

 

Very Easy 8 or less 123 comics 5th 90
Easy a 131 pulp fiction 6th 86
Fairly Easy 14 139 slick fiction 7th 80
Standard L7 147 digests 8th & 9th 7S
Rairly.Dittioult 21 155 quality 10th-12th 40
Difficult 25 167 academic 13th-16th 24

 

 

Very Difficult 29 or more 192 scientific Graduate Aol

 

 

 

 

If you would like a more detailed analysis of the readability and organization of your
textbook, send a copy to David Barnett on the Richmond Campus. He will use a more complex

formula and return the textbook with a report within a week or so.