The following is reposted with permission of the American Federation 
of Teachers (http://www.aft.org)
                              August 29, 1996
FOR RELEASE: Immediately
                        Statement by Albert Shanker
                 President, American Federation of Teachers
   on the Greene/Peterson study of the Milwaukee school voucher program
The conflicting evaluations of the Milwaukee voucher program are not just a
fight between statisticians. Research is an important tool that is supposed
to help citizens and policymakers make wiser decisions about important
public issues. The subject of this Milwaukee research is how best to
improve the education of poor children, one of the most pressing social
issues we face in America. Children's lives and futures are at stake. So it
behooves researchers involved in this issue to do their work with utmost
honest and integrity. But the work of Jay Greene at the University of
Houston and Paul Peterson of Harvard ignores this ethical necessity.
Greene/Peterson claim that students in the Milwaukee voucher program do
better than comparable public school students in the 3rd and 4th years of
the program. Although they are looking at the same data, Greene/Peterson's
results contradict four years' worth of careful evaluations by researcher
John Witte of the University of Wisconsin. Witte has found no difference in
achievement between voucher students and comparable public school students
in any year of the program. The Greene/Peterson study also contradicts
about 30 years of research on public/private school differences in student
achievement.
Who's right? Greene/Peterson violate some of the most basic rules of
research on student achievement. First, in their main analysis -- the one
on which they base their conclusions -- they fail to take account of family
background, which has proven to be one of the most powerful influences on
student success in school. Controlling for family background is the only
way researchers can separate school influences on student performance from
family influences. Second, Greene/Peterson further stack the deck by using
a statistical standard that is much lower than researchers ordinarily use^
or accept. Even then, their analysis fails to prove their claim, despite
what they say in their report.
The deception continues. Though they don't report it, Greene/Peterson
include an analysis in the back of their paper that does take account of
family background. Their results are identical to Witte's conclusion: no
difference in achievement between voucher students and their public school
peers. This holds true both according to Greene/Peterson's lax statistical
standard and to the accepted, more stringent standard.
What else don't they tell us? Huge numbers of voucher students -- as much
as 30 percent a year -- dropped out or were pushed out of their private
schools over the four years. Similarly, by the third and fourth year, very
few of the public school students Greene/Peterson originally looked at were
left in the study. By the third and fourth year, then, Greene/Peterson
based their conclusion on only a handful of students -- in some cases, as
few as 0-3 per grade! But they don't fess up to these pitifully small
numbers, which make it impossible to draw any reliable conclusions. Basing
public policy on these results would be like urging a whole population to
take a new medicine when you've only tried it out on a small group -- and
found that it didn't even work with them!
Greene and Peterson also neglect to report that they do not include all the
private schools that participated in the voucher program. The number of
private schools in the program has ranged from a low of 11 to a high of 16.
Four of these schools have closed, three under a cloud of financial and
educational irregularities. The head of one voucher school fled the scene
and was recently arrested in Texas. When you're promoting a market approach
to education, a 25 percent failure rate is an important piece of
information.
Greene/Peterson's violations of professional standards are just as
disturbing. They claim that Witte withheld the data from other researchers,
but the data have been available since 1992. Witte's research has been
subjected to professional review for more than four years. Greene and
Peterson released their study to voucher advocacy groups and the media
before it was subjected to professional review, which is highly unorthodox
among scientists. Every researcher who has looked at it since then has
demolished it. The 'errors,' omissions, and distortions in the
Greene/Peterson study suggest that, rather than a search for the truth,
their motivation is political and ideological.
The American Federation of Teachers represents 907,000 teachers, school
support staff, higher education faculty and staff, healthcare
professionals, and state and municipal employees.
                                   # # #
Chuck Beams
Fidonet - 1:2608/70
cbeams@future.dreamscape.com
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* UniQWK #5290* Your family's Coat-of-Arms ties in the back - is that normal?
--- Maximus 2.01wb
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