I am looking into the topic "What constitutes 'expertise' in the field
of 'Composition Studies'?" I am interested in two related data-sets:
(1) What percentage of freshman/sophomore composition classes in
"major" universities (in this case, those with a graduate program in
English) are taught by full-time tenured or tenure-track instructors;
and (2) do those scholars who publish articles in the major academic
journals dealing with composition teaching, as well as those who are
routinely anthologized in collections of such pieces, REGULARLY teach
the students and courses they write about?  The questions are related,
but the second one -- my primary interest -- would be more difficult
to research, most likely, than the first one. An acceptable researched
"answer" to these questions would require, of course, sufficient data
to "warrant" a "claim" (as we in the field put it) regarding whether
there is or is not a notable disconnect between the expert theorizing
and the pedagogical practicing that goes on in this field -- that is,
are the designated (through publication, primarily) experts in the
field REGULAR PRACTITIONERS of the teaching they theorize about?
(Typically, in any field such a combination of theorizing and
application is a central criterion for the attribution of
"expertise.")  A collection of names gleaned from a scanning of the
recent scholarly "literature" found in appropriate academic journals
(e.g., "College Composition and Communication") would provide a list
of universities to focus on for Question #1. Another angle would be to
determine whether the people who do most of the actual teaching of
these courses are doing most of the publishing -- that is, having a
strong say in establishing what is considered legitimate EXPERT
pedagogical theory & practice in this field. I'm sure my "working
hypothesis" here is obvious (something about a "disconnect"), but as a
professional in the field I would be happy to be proved wrong.  I does
strike me as an important question, seeing as it affects the literacy
education of thousands of our college students.

Hello jaydeepaco,

Thank you for your question.

This caught my eye because I also find it interesting that the most
widely-published professors and researchers are not the ones teaching
students at their universities, almost out of necessity-- if you're
spending so much time in the laboratory or the library, you can't
teach a class full of undergrads at the same time.

Anyway, the best way to answer your first question is through the
National Study of Postsecondary Faculty, which is released on a yearly
basis.  The latest study available is from 2004.  According to its
findings,

2004 National Study of Postsecondary Faculty
http://nces.ed.gov/pubsearch/pubsinfo.asp?pubid=2005172

This study found that in 1998 to 2003, percentages of full-time
tenured professors that teach had increased 33 percent, and that
contingent and part-time professors composed 25% of the teaching staff
at four-year colleges.

The MLA (Modern Language Association), which most English professors
would be a part of, commissioned a survey in 1999 on just this very
subject, and it is the latest survey data available for English
professors in general.  The MLA conducted the study for PhD-granting
institutions, which would be what you are interested in.  To gain a
good rating, a school must have more than 46% of undergraduate classes
taught by tenured faculty.  The average for research universities was
that 30.5% of classes were taught by tenured faculty.  The percentage
of associate degree-granting colleges was higher, at 31%.  Only at
four-year colleges that do not grant graduate degrees was the
percentage highest, with 53.6% of tenured faculty teaching classes.

The survey can be accessed in its entirety here:
MLA Survey
http://www.mla.org/staffing_survey99

Another survey from the following year found that humanities subjects
such as English have the lowest rates of tenure faculty in teaching
positions-- with percentages ranging from 7% to 34% of undergraduate
classes.

Chronicle of Higher Education
"Report Details Colleges' Heavy Reliance on Part-Time Instructors"
http://depts.washington.edu/uwaaup/parttime2.htm

For the second part of your question, while that is probably
definitively answered by the previous figures, I've looked at the
Norton Anthologies and yearly prizes that the MLA gives out-- this
should lead us to the top English scholars in the nation.  The answer
seems to be that while MOST classes are taught by adjunct rather than
tenured professors, the most distinguished scholars in the field DO
teach undergraduate classes, in some cases to an astonishing degree. 
Here is a sampling:

The definitive way to find the most important English professors is by
looking at the different Norton Anthologies, which are used as
textbooks in a vast amount of collegiate English classes and are
edited by distinguished professors in the discipline.

The preeminent English scholar of the current day is Stephen
Greenblatt, a Shakespearean and Renaissance scholar familiar to any
English major, who edits "The Norton Anthology of English Literature",
"The Norton Shakespeare" and "English Literature: Major Authors".  He
is Cogan University Professor of the Humanities at Harvard University.
 He teaches classes and his plan for team-teaching an introductory
course at Harvard in fall 2006 is outlined in this article:

Harvard Magazine
"Reconfiguring the Curriculum"
http://www.harvardmagazine.com/on-line/070666.html 

The following three professors are creators of the William Blake
Archive, an extremely important literature resource.
William Blake Archive
http://www.blakearchive.org/blake/

*Morris Eaves, University of Rochester
http://www.rochester.edu/college/eng/faculty/eaves.html
According to his website, Eaves does in fact teach undergraduate
classes.  He taught British Romanticism in Spring 2006.

*Robert N. Essick, University of California- Riverside
Essick is a Professor Emeritus (retired professor).

*Joseph Viscomi, University of North Carolina at Chapel Hill
Viscomi does teach classes, although he has a sabbatical next year in Italy.
http://english.unc.edu/faculty/viscomij.html

*Priya Joshi won the MLA First Book Prize and is well-known for her
work in Indian studies--
she does teach a few different classes at Temple University and here is an example:
http://astro.temple.edu/~pjoshi/english244_f05.html

*Steven Justice is a previous recipient of the MLA First Book Prize. 
The last record of his teaching a class that I can find is in 2002.

*Barbara Lewalski is a renowned Milton scholar and Norton editor.  She
is teaching an English class in the 2006-2007 school year.
Harvard Course Schedule
http://www.fas.harvard.edu/~histlit/courses-that-count.html

*James Simpson, a Harvard professor, Norton editor, and Cambridge Life
Fellow, teaches Chaucer classes.
http://www.fas.harvard.edu/~english/people/simpson_profile.htm

This is only a sampling, but it seems clear that even the most
distinguished professors, with plenty of work besides teaching to keep
them occupied, do make time to teach at least one class a year.

Sources:

Academic Work Force
http://www.academicworkforce.org/research_reports/index.cfm

Academe Online
http://www.aaup.org/AAUP/pubsres/academe/2006/ND/Feat/sidebar2.htm

UC Riverside English Professors
http://english.ucr.edu/people/faculty/index.html

MLA Awards Prize to Blake Archive
http://www.iath.virginia.edu/news_blake.html

University of California at Berkeley Press Release
http://www.berkeley.edu/news/media/releases/2003/12/02_twain.shtml

Search terms:
"mla survey of staffing in english"
english professors teaching undergraduate classes tenure
english literature mla awards
morris eaves
site:ucr.edu robert n essick
joseph viscomi
greenblatt teaching classes harvard
priya joshi
steven justice berkeley
barbara lewalski site:harvard.edu 

This is my very last question for Google Answers, so it's a special
question for me!  If you need any additional clarification, let me
know and I'll be glad to assist you.

--keystroke-ga