Edward Fry’s Readability Graph shows the approximate grade levels from 1 to 17+. This graph is discussed in William DuBay’s book Smart Language and may be easily found online. Its variables are the percentage of syllables on the x-axis and the percentage of sentences on the y-axis. A simple count of the number of syllables in 100 words yields the percentage of syllables, but finding out the percentage of sentences needs a little arithmetic as 100-word samples seldom end with a full stop.
Suppose a 100-word sample has 4 complete sentences of 92 words and a sentence-fragment of 8 words, then the percentage of sentences is (4/92) x 100 = 4.34. Now if the sample has 132 syllables, then the zone on the graph where the two coordinates meet shows a grade level of 8.
The Fry Graph is easy to use, but it can be made easier with different variables. Let us begin with the x-axis. Rudolph Flesch, in an article ‘A New Readability Yardstick’, published in the Journal of Applied Psychology (3 June 1948), suggested a simple syllable-counting procedure: “To save time, count all syllables except the first in all words of more than one syllable and add the total to the number of words tested.” So if a 100-word sample has 132 syllables, there will be only 32 exsyls (excess syllables).
Irving Fang’s Easy Listening Formula and Davis Foulger’s Simplified Flesch Reading Ease use exsyls as a variable. I followed their example and incorporated the exsyls in the Flesch-Kincaid Index. So why should not the Fry Graph take advantage of the exsyls? Replacing the percentage of syllables with the percentage of exsyls is easily done by subtracting 100 from each of the numbers marked on the x-axis. Or simply erase the 100th digit. So the new numbers on the x-axis are 08, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, 80 and 82.
Now, let us move on to the y-axis. There is an exact equation between the average number of words per sentence (AWS) and the number of sentences in 100 words (S%). And here it is: AWS = 100 / (S%). If a 100-word sample ends with a full stop, then S% is easier to calculate than AWS. But this happens in the rarest of rare cases. Since 100-word samples are reluctant to end with a full stop, AWS is easier to calculate than S%. Robert Gunning’s Fog Index, Flesch-Kincaid Index, Smith and Senter’s Automated Readability Index are some formulae that use the AWS. So why should not the Fry Graph take advantage of the AWS too?
Using the formula AWS = 100 / (S%), the number of sentences per 100 words may be replaced with the AWS. For example, 4.8 shall be replaced with 20.83 [100 / 4.8]. Likewise, the other numbers on the y-axis shall also be replaced.
The exsyls are easy to count and the AWS is easy to calculate. With these variables, I hope that the deservedly popular Fry Graph may become even more popular.