style - Man Page

Style understands cpp(1) #line lines for being able to give precise locations when printing sentences.

Kincaid formula

The Kincaid Formula was developed for Navy training manuals, that ranged in difficulty from 5.5 to 16.3.  It is probably best applied to technical documents, because it is based on adult training manuals rather than school book text.  Dialogs (often found in fictional texts) are usually a series of short sentences, which lowers the score.  On the other hand, scientific texts with many long scientific terms are rated higher, although they are not necessarily harder to read for people who are familiar with those terms.

$\text{Kincaid}=11.8*\frac{syllables}{words}+0.39*\frac{words}{sentences}-15.59$

Automated Readability Index

The Automated Readability Index is typically higher than Kincaid and Coleman-Liau, but lower than Flesch.

$\text{ARI}=4.71*\frac{letters}{words}+0.5*\frac{words}{sentences}-21.43$

Coleman-Liau Formula

The Coleman-Liau Formula usually gives a lower grade than Kincaid, ARI and Flesch when applied to technical documents.

$\text{Coleman-Liau}=5.88*\frac{letters}{words}-\frac{29.5*sentences}{words}-15.8$

Flesh reading easy formula

The Flesh reading easy formula was developed by Flesh in 1948 and it is based on school text covering grade 3 to 12.  It is wide spread, especially in the USA, because of good results and simple computation. The index is usually between 0 (hard) and 100 (easy), standard English documents averages approximately 60 to 70.  Applying it to German documents does not deliver good results because of the different language structure.

$FleschIndex=206.835-84.6*\frac{syllables}{words}-1.015*\frac{words}{sentences}$

Fog Index

The Fog index was developed by Robert Gunning.  Its value is a school grade.  The “ideal” Fog Index level is 7 or 8.  A level above 12 indicates the writing sample is too hard for most people to read. Only use it on texts of at least hundred words to get meaningful results. Note that a correct implementation would not count words of three or more syllables that are proper names, combinations of easy words, or made three syllables by suffixes such as –ed, –es, or –ing.

$FogIndex=0.4*\left(\frac{words}{sentences}+100*\frac{words\ge 3syllables}{words}\right)$

Lix formula

The Lix formula developed by Björnsson from Sweden is very simple and employs a mapping table as well:

$Lix=\frac{words}{sentences}+100*\frac{words>6characters}{words}$

Index	34		38		41		44		48		51		54		57
School year		5		6		7		8		9		10		11

SMOG-Grading

The SMOG-Grading for English texts was developed by McLaughlin in 1969.  Its result is a school grade.

$\text{SMOG-Grading}=\sqrt{\frac{(words\ge 3syllables)}{sentences}*30}+3$

It has been adapted to German by Bamberger & Vanecek in 1984, who changed the constant +3 to -2.

The word usage counts are intended to help identify excessive use of particular parts of speech.

Verb Phrases

The category of verbs labeled "to be" identifies phrases using the passive voice.  Use the passive voice sparingly, in favor of more direct verb forms. The flag -p causes style to list all occurrences of the passive voice.

The verb category "aux" measures the use of modal auxiliary verbs, such as "can", "could", and "should".  Modal auxiliary verbs modify the mood of a verb.

Conjunctions

The conjunctions counted by style are coordinating and subordinating. Coordinating conjunctions join grammatically equal sentence fragments, such as a noun with a noun, a phrase with a phrase, or a clause to a clause. Coordinating conjunctions are "and," "but," "or," "yet," and "nor."

Subordinating conjunctions connect clauses of unequal status.  A subordinating conjunction links a subordinate clause, which is unable to stand alone, to an independent clause.  Examples of subordinating conjunctions are "because," "although," and "even if."

Pronouns

Pronouns are contextual references to nouns and noun phrases.  Documents with few pronouns generally lack cohesiveness and fluidity.  Too many pronouns may indicate ambiguity.

Nominalizations

Nominalizations are verbs that are changed to nouns.  Style recognizes words that end in "ment," "ance," "ence," or "ion" as nominalizations. Examples are "endowment," "admittance," and "nominalization."  Too much nominalization in a document can sound abstract and be difficult to understand. The flag -N causes style to list all nominalizations.  The flag -n prints all sentences with either the passive voice or a nominalization.