Subject: Re: Time to update KNF?
To: None <>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-kern
Date: 01/18/2000 10:55:11
> I think the Bottom Line is: 8-space tabs produces less comprehensible
> code by 20% to 30% compared with the same code indented 2 to 4
> spaces.

That's not how it was reported.  Here's the quote:

"Subjects scored 20 to 30 percent higher on a test of comprehension when
 programs had a two-to-four-spaces indentation scheme than they did when
 programs had no indentation at all.

"The same study found that it was important to neither under-emphasize nor
 over-emphasize a program's logical structure.  The lowest comprehension
 scores were achieved on programs that were not indented at all.  The second
 lowest were achieved on programs that used six-space indentation.

Nothing about 8-space indentation, though the extension from six-space
seems plausible.

Without seeing more details, I can't also tell whether perhaps they
were using different programs that happened to use those indentation
styles, in which case the study is simply meaningless - the six-space
code may simply have been inherently more difficult to understand.
(This strikes me as the sort of mistake a non-computer-literate
researcher could easily make, but be sufficiently unaware of to neglect
to mention.)

Or, perhaps, the code was written at four spaces, then mechanically
reformatted to six - which, if the original coder was any good, will
probably damage its comprehensibility for reasons unrelated to the

And how were the subjects selected?  What matters to your average psych
experiment subject may matter less - or more - to a competent
experienced programmer, such as I would hope most of the people dealing
with KNF are.

And how was "comprehension" measured?

In short, we don't have enough information to draw any conclusion
relevant to the discussion.

> If somebody has factual data that refutes [this] [...]

> Else, I believe, regardless of our collective prejudices, the facts
> remain.

Yes...but it's not clear whether those facts are actually relevant to
the discussion.

					der Mouse

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