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<!--#exec cmd="header style" -->
<ul>
</ul><H2>NAME {{{roff}}}{{{ </H2><ul>

style - analyse surface characteristics of a document

</ul><H2>SYNOPSIS {{{ </H2><ul>

<b>style</b> 
[<b>-L</b>
<i>language</i>]
[<b>-l</b>
<i>length</i>]
[<b>-r</b>
<i>ari</i>]
[<i>file</i>...]
<br>
<b>style</b> 
[<b>--language</b>
<i>language</i>]
[<b>--print-long</b>
<i>length</i>]
[<b>--print-ari</b>
<i>ari</i>]
[<i>file</i>...]
<br>
<b>style</b> 
<b>-h</b>|<b>--help</b>
<br>
<b>style</b> <b>--version</b> 

</ul><H2>DESCRIPTION {{{ </H2><ul>

<b>Style</b> analyses the surface characteristics of the writing style
of a document.  It prints various readability grades, length of words,
sentences and paragraphs.
It can further locate sentences with certain characteristics.
If no files are given, the document is read from standard input.

<p>
Numbers are counted as words with one syllable.
A sentence is a sequence of words, that starts with a capitalised word and
ends with a full stop, double colon, question mark or exclaimation mark.
A single letter followed by a dot is considered an abbreviation, so it
does not end a sentence.  Various multi-letter abbreviations are
recognized, they do not end a sentence as well.
A paragraph
consists of two or more new line characters.

<p>
<b>Style</b> understands <i>cpp</i>(1) <b>#line</b> lines for being able to
give precise locations when printing sentences.

</ul><H2>Kincaid Formula {{{ </H2><ul>

The Kincaid Formula has been 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 neccessarily harder to read for people
who are familar with those terms.

<p>
<ul>italic "Kincaid" = 11.8 * syllables over words + 0.39 * words over sentences - 15.59
</ul>Kincaid = 11.8*syllables/wds+0.39*wds/sentences-15.59

</ul><H2>Automated Readability Index {{{ </H2><ul>

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

<p>
<ul>italic "ARI" = 4.71 * letters over words + 0.5 * words over sentences - 21.43
</ul>ARI = 4.71*chars/wds+0.5*wds/sentences-21.43

</ul><H2>Coleman-Liau Formula {{{ </H2><ul>

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

<p>
<ul>italic "Coleman-Liau" = 5.89 * letters over words - 0.3 * sentences over { 100 * words } - 15.8
</ul>Coleman-Liau = 5.89*chars/wds-0.3*sentences/(100*wds)-15.8

</ul><H2>Flesh reading easy formula {{{ </H2><ul>

The Flesh reading easy formula has been 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.

<p>
<ul>Flesch ~ Index = 206.835 - 84.6 * syllables over words - 1.015 * words over sentences
</ul>Flesch Index = 206.835-84.6*syll/wds-1.015*wds/sent

</ul><H2>Fog Index {{{ </H2><ul>

The Fog index has been 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.

<p>
<ul>Fog ~ Index = 0.4 * left ( words over sentences + 100 * { { words &gt;= 3 ~ syllables } over words } right )
</ul>Fog Index = 0.4*(wds/sent+100*((wds &gt;= 3 syll)/wds))

</ul><H2>WSTF Index {{{ </H2><ul>

The first new Vienna text formula (1. neue Wiener Sachtextformel, WSTF)
has been developed for German documents and its result is a school grade
that could read the text.

<p>
<ul>matrix {
col { WSTF ~ Index = above ~ }
lcol {
0.1935 * { words &gt;= 3 ~ syllables } over words + 0.1672 * words over sentences -
above 
down 70 { 0.1297 * { words &gt; 6 ~ characters } over words - 0.0327 * { words = 1 ~ syllable } over words - 0.875 }
}
}
</ul>WSTF Index =  0.1935*(wds &gt;= 3 syllables)/wds
             +0.1672*wds/sent
             -0.1297*(wds &gt; 6 characters)/wds
             -0.0327*(wds = 1 syllable)/wds
             -0.875

</ul><H2>Wheeler-Smith Index {{{ </H2><ul>

The Wheeler-Smith Index is mapped to school grades using a table:

<p>
<ul>italic "Wheeler-Smith" ~ Index =
{ words over sentences * { words &gt;= 3 ~ syllables } over words } over 10
</ul>Wheeler-Smith Index = wds/sent*(wds &gt;= 3 syll)/wds/10

<p>
<ul>tab(#);
l c c c c c c c c c c c c c.
Index#16##20##24##29##34##38##42
School year##5##6##7##8##9##10
</ul>
</ul><H2>Lix formula {{{ </H2><ul>

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

<p>
<ul>Lix =
words over sentences + { words &gt; 6 ~ characters } over words
</ul>Lix = wds/sent+(wds &gt;= 6 char)/wds

<p>
<ul>tab(#);
l c c c c c c c c c c c c c c c.
Index#34##38##41##44##48##51##54##57
School year##5##6##7##8##9##10##11
</ul>
</ul><H2>SMOG-Grading {{{ </H2><ul>

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

<p>
<ul>italic "SMOG-Grading" = sqrt { (words &gt;= 3 ~ syllables) * sentences over 30 } + 3
</ul>SMOG-Grading = square root of ((wds &gt;= 3 syll)*sent/30) + 3

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

</ul><H2>OPTIONS {{{ </H2><ul>

<p><dl compact><dt><b>-L</b> <i>language</i>, <b>--language</b> <i>language</i><dd>set the document language.
<dt><b>-l</b> <i>length</i>, <b>--print-long</b> <i>length</i><dd>print all sentences longer than <i>length</i> words.
<dt><b>-r</b> <i>ari</i>, <b>--print-ari</b> <i>ari</i><dd>print all sentences whose readability index (ARI) is greater than <i>ari</i>.
<dt><b>-h</b>, <b>--help</b><dd>Print a short usage message.
<dt><b>--version</b><dd>Print the version.
</dl>
</ul><H2>ERRORS {{{ </H2><ul>

On usage errors, 1 is returned.  Termination caused by lack of memory is
signalled by exit code 2.

</ul><H2>ENVIRONMENT {{{ </H2><ul>

<p><dl compact><dt><b>LC_MESSAGES</b>=<b>de</b>|<b>en</b><dd>specifies the default document language.  The default language is <b>en</b>.
<dt><b>LC_CTYPE</b>=<b>iso-8859-1</b><dd>specifies the document character set.  The default character set is ASCII.
</dl>
</ul><H2>AUTHOR {{{ </H2><ul>

This program is GNU software, copyright 1997, 1998
Michael Haardt (michael@cantor.informatik.rwth-aachen.de).

<p>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

<p>
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

<p>
You should have received a copy of the GNU General Public License along
with this program.  If not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

</ul><H2>HISTORY {{{ </H2><ul>

There has been a style command on old UNIX systems, which is now part
of the AT&amp;T DWB package.  The original version was bound to roff by
enforcing a call to deroff.

</ul><H2>SEE ALSO {{{ </H2><ul>

deroff(1), diction(1)

<p>
Cherry, L.L.; Vesterman, W.: <i>Writing Tools The STYLE and DICTION
programs</i>, Computer Science Technical Report 91, Bell Laboratories,
Murray Hill, N.J. (1981), republished as part of the 4.4BSD User's
Supplementary Documents by O'Reilly.
</ul>
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