A new readability formula for Measuring Incomprehension of Sample Text — the MIST Index. I have based this formula, which grades texts on a scale of 1 to 17+, on two variables: the number of words in four sentences (W4) and the number of clauses in as many sentences (C4).
MIST Index = (W4/10) + C4 – 4.
Let us apply the formula on a sample from the Manifesto of the Communist Party:
A spectre is haunting Europe — the spectre of Communism. All the Powers of old Europe have entered into a holy alliance to exorcise this spectre: Pope and Czar, Metternich and Guizot, French Radicals and German police spies.
Where is the party in opposition that has not been decried as Communistic by its opponents in power? Where is the Opposition that has not hurled back the branding reproach of Communism, against the more advanced opposition parties, as well as against its reactionary adversaries?
W4 = 82; C4 = 6. MIST Index = (82/10) + 6 – 4 = 10.2.
Harry McLaughlin’s SMOG Grading is based on the number of polysyllabic words in 30 sentences. Since there are 12 polysyllabic words in four sentences, it may be assumed that there are 90 polysyllabic words in 30 sentences. SMOG Grading = (square root of 90) + 3 = 12.48.
Robert Gunning’s Fog Index uses the average words per sentence (AWS) and the percentage of hard words (H%), which are polysyllabic words — excluding capitalized words, easy compound words and verbs made trisyllabic by adding ‘-es’ or ‘-ed’. In our sample AWS = 82/4 = 20.5; and H% = (6/82) x 100 = 7.31. Fog Index = 0.4 x (AWS + H%) = 0.4 x (20.5 + 7.31) = 0.4 x 27.81 = 11.12.
Clear writing is not foggy/smoggy/misty. Isn’t the MIST Index an easy formula for Measuring Incomprehension of Sample Text?