Re: Readability indices, take II

[Steven Jong <SteveFJong -at- AOL -dot- COM>]

[As I sit here at home with a cold, I have nothing better to do than pick nits
with Geoff 8^) ] He wrote:

>> First, I suggested  randomizing the words:
>> "the dog is white" becomes "white the is dog",
>> which is hardly readable despite having an
>> identical readability index.

Well... It's meaningless, but it's still readable. Perhaps a more interesting
example is "White is the dog," which is semantically the same and equally
readable according to the index, but a little more difficult to read. Why?
Because it's a right-to-left branching sentence: the object precedes the verb
and the verb precedes the subject. (This is also known as a passive-voice
sentence.) Although sentences can be constructed to branch left, right, or
center, they are easiest to understand when they branch left-to-right. For
this assertion there is experimental verification and theoretical support.
Backward-branching sentences tax the reader's short-term memory. (Spoofing
Time magazine's house style, someone once wrote, "Backward ran the sentences
until reeled the mind.") This burden is especially true for readers of English
as a second language. The link between complex sentence structure and
readability is causal: complex sentences are inherently less readable.

Now, non-straightforward and complex sentences are characteristically longer
than straightforward, simple sentences. This is a correlation, not a causal
link, but it's a strong one. It takes a good writer to construct a long
sentence that is still easy to read and understand. (In teaching my seminar on
documentation quality, I like to read the first sentence of Dickens's _Tale of
Two Cities_: "It was the best of times, it was the worst of times..." It goes
on for 212 words, if memory serves, but it's quite readable.)

>> Second, I suggested changing word
>> order to reverse the meaning: "the dog is not white" becomes
>> "is not the dog white[?]". I don't know of any language in
>> which readability is independent of meaning; in fact, I define
>> readability as the ease with which the text communicates the
>> author's desired meaning.

I disagree--readability is always independent of meaning. I would agree that
poor readability obscures meaning, which clearly we don't want. I guess I
would define readability the same way you do, though. I can even suggest a
worse example for you: readability indices will give the same results if you
enter the sentences completely backward; they will give results, though
meaningless, for samples in any Romance language.

>> What do I want? An index that
>> does more than count words and spaces. That's useless, as I
>> hope my two examples have just shown.

Actually, most indexes count words and syllables. I think I have shown a
correlation between sentence length and readability based on sound theory.
What about syllable counts? Reading is a process of decoding symbolic meaning.
Adding synonyms, jargon, and Latinates makes the decoding more difficult. I
can write, "He delivered the horsehide sphere" when I mean to say "He threw
the baseball," but I'm going to lose readers along the way. It's pretty well
established that using ornate language and polysyllabic words obscures
meaning; again, it's especially true for foreign readers. This correlates
strongly to syllable counts. When Strunk told us to prefer simple words, he
knew what he was about.

So the combination of measuring sentence length and syllable counts has a
basis in theory.

>> There's almost no correlation between the main
>> readability indexes and actual readability, and there won't be
>> for a good long time to come until someone develops a tool
>> that can parse the content of text in the specific context of a
>> well-defined audience.

This is important work that I believe has yet to be done. I participated in
the study of one such tool, which required measurements of some two dozen
characteristics, including passive-voice sentences, sentences with an explicit
agent of action, and many others. I believe it was well grounded, but it took
me hours to get results for a single document. As you wrote:

>> I consider the indices of
>> so little use that I'd rather pay a good editor to have a read
>> through the manuscript and tell me if it's appropriate for my
>> audience.

I would, too; but have you priced an editor lately? The readability index is
simple-minded but very quick and easy to use.  For working professionals,
quick and dirty metrics have advantages.

Having said all that, I would be the first to man the battlements if someone
declared that readability was the only important consideration for my
documents. I am just conducting an academic defense of readability in a
limited role as part of a larger set of documentation metrics and assessments.

          -- Steve

=========|=========|=========|=========|=========|=========|=====
Steven Jong, Documentation Team Manager ("Typo?  What tpyo?")
Lightbridge, Inc., 67 South Bedford St., Burlington, MA 01803 USA
mailto:jong -at- lightbridge -dot- com -dot- nospam          781.359.4902 [voice]
Home Sweet Homepage: http://members.aol.com/SteveFJong


 From ??? -at- ??? Sun Jan 00 00:00:00 0000=