Grade levels are from 1 to 17+. Comfort levels are E (easy), S (standard) and H (hard). Two texts of the same grade level may have different comfort levels. So a readability formula that reckons only the grade level — and ignores the comfort level — gives us an incomplete picture of reading difficulty. I have, therefore, derived the Grade-Comfort Level (GCL), which not only grades texts but also indicates the comfort level.
First, we calculate:
- The average number of words per sentence
- The average number of syllables per sentence (s)
- Q(w/2), quotient of w divided by 2
- Q(s/3), quotient of s divided by 3
Then, we compare Q(w/2) and Q(s/3). The grade and comfort levels depend on whether Q(w/2) is less than or equal to or greater than Q(s/3). If Q(w/2) is less, then the grade level is Q(s/3) and the comfort level is H. If Q(w/2) is more, then the grade level is Q(w/2) and the comfort level is E. The third possibility is Q(w/2) = Q(s/3) = grade level; and the comfort level is S.
If this sounds a little complicated, let us just take a few single-sentence samples for clarification. But remember that to get accurate results, longer samples are required.
Sample 1 (from Arthur Conan Doyle’s The Adventure of the Greek Interpreter): “During my long and intimate acquaintance with Mr. Sherlock Holmes I had never heard him refer to his relations, and hardly ever to his own early life.”
Q(w/2) = Q(27/2) = 13; Q(s/3) = Q(41/3) = 13. Since the scores are equal, GCL = 13 S.
Sample 2 (from Agatha Christie’s The Affair At the Victory Ball): “Pure chance led my friend Hercule Poirot, formerly chief of the Belgian force, to be connected with the Styles case.”
Q(w/2) = Q(20/2) = 10; Q(s/3) = Q(27/3) = 9. Since Q(w/2) is more, GCL = 10 E.
Sample 3 (from G.K. Chesterton’s The Chief Mourner of Marne): “A blaze of lightning blanched the grey woods tracing all the wrinkled foliage down to the last curled leaf, as if every detail were drawn in silverpoint or graven in silver.”
Q(w/2) = Q(31/2) = 15; Q(s/3) = Q(42/3) = 14. Since Q(w/2) is more, GCL = 15 E.
I have not explained the basis of this formula. For those who are curious, the GCL is connected with the Flesch Reading Ease and mine own Strain Index. If you are more curious, just email me!