RE: Numbering the headings. What is the point?

["Murrell, Thomas" <TMurrell -at- alldata -dot- net>]

Martin Smith writes:

> Earlier in my career I used to write component maintenance manuals used to
> maintain components of civilian and military aircraft. The military people
> that I worked around were quite adapt at quoting the section numbers of
> the
> documents that they used regularly, much as some people are able to quote
> chapter and verse from scripture. The elaborate numbering system assigned
> to
> military documents allows people to memorize the relevant section numbers
> and turn to them immediately. Section numbers are also handy in
> emergencies,
> for example when an airline pilot and the ground crew must consult
> emergency
> landing procedures, or when the cooling pumps fail in a nuclear power
> plant... One saves precious seconds knowing that section 3.4.1.3 will
> always
> tell you what to do when component xyz breaks.
> 
Here I will concede is a bit of anecdotal data I can understand in favor of
numbered heads.  The problem is that all we seem to have, or at least all
that is being presented, is anecdotal.  What that means is that I am
supporting my prejudices with "data" that suits me.  I plead as guilty of
this approach as anyone else, so I am not casting aspersions.

Does anyone have actual analytical data to support their position, though?
Has anyone actually done an unbiased study?  If not, I nominate this
question as another one for our wish list to the academics.

Regards,
Tom Murrell
Etc. & Ad Nauseum