I have some observations to make about Brock's distinction.

If we read just this far in his definition of private grammar,

> Private grammar refers to the language ability that normal, native users
> possess--the more linguistic view of grammar, whether structural or
> functional.  It is private in the sense that we emphasize its innateness and
> its relevance to the writer's personal command of language.

does public school teach it?

I am not in the public schools.  In my college level writing classes, I
never try to teach a student just her private grammar.  Who should
interfere with it as defined here by Brock?

I agree with Brock's definition of public grammar, but I think this
definition fails to recognize the fundamental value of the existence of
a "public grammar".

> By Public grammar, I mean traditional prescriptive grammar as it generally
> appears in the handbooks and as it is applied in the final editing phase of
> writing.  I see it as "public" in the sense that it reflects the certain
> conventions of literacy and the standard dialect that society recognizes.

Of course, it has certain conventions, but those conventions are
necessary for any communication to take place across different speech
communities.  Having those conventions are of value for solving
"Caxton's problem."  Caxton was the first printer of English and faced
an enormous problem.  How should he represent an oral language with vast
dialect differences on the printed page?  Which dialect provides a model
for conventions which the widest number of speakers of English can
understand?  Despite the kind of social inequalities that privileging
one dialect over all others creates, having a set of agreed conventions
provides EVERYONE who is a proficient speaker of English to read the
work of anyone else who is a proficient speaker of English.  See Deborah
Cameron's Verbal Hygiene for a discussion of this point.  (This was the
point Jim Kenkel and I tried to make in our paper last year at ATEG.)

Unless I have missed something, one of the important goals of public
education is to provide students with the skills necessary to engage in
discourse in the widest possible public communities.  In a country with
a deep commitment to democratic decision-making, conventions of language
of the widest possible speech communities allows EVERYONE to have her
ideas considered.  See Richard Rodriguez's Hunger of Memory for the
value of knowing the public language.

I guess this makes me a prescriptivist, but as Jim and I said last year,
we all are.  After all, does anyone of us read a newspaper or an
academic journal which does not follow certain conventions of standard
written English.  Of course, sometimes we encounter examples in which
the conventions of public grammar are deliberately violated.  When that
happens in those places ain't there usually a good reason?  Sometimes,
it is to deliberately challenge the convention.  In other words, it is
sometimes appropriate to be inappropriate.

So, as a self-confessed prescriptivist, I think Brock is too restrictive
with the importance of public grammar.

> In the teaching of writing, public grammar comes into play in the final
> editing/proofreading process, where the paper is made ready to go on to the
> public stage.  Private grammar still seeks a place in the process, as we are
> discussing: it fits in the composing or revising processes, but those
> processes are already busy and difficult to teach.

Being able to control the conventions of public grammar, especially in
writing, is one of the important goals of education because its
conventions are expected to be understood by the writer (not necessarily
always followed) when a text is to appear on the public stage.  I
readily admit that any public text must do more than follow the
conventions of public grammar.  A text which is confusing, not
well-organized, not well-supported, and/or boring will not be well
received on the public stage either.   That is the great problem in
writing instruction.  Complete knowledge about the conventions of public
grammar does not guarantees that a text will be clear, organized with
good arguments and/or interesting.

Finally, Brock reminds us of the particular values we Americans have and
especially the value we want to put on everyone's ideas regardless of
the form those ideas are expressed in.

> And America in particular has
> its own very quirky expectations about individualism and the realm of the
> private, versus conformity.  No wonder the grammar battle is tough.

Bob Yates