Dick,

A couple of weeks ago you sent me an e-mail
with values of $\alpha_S$ versus $Q$, and asked
whether the CTEQ program has different values.

I've put a postscript figure on a web page that
compares your values of $\alpha_S$ to the values
of $\alpha_S$ in the CTEQ program.  The black dots
are your numbers, and the red dots are CTEQ. There
are small differences at small $Q$. The web page is
www.pa.msu.edu/people/stump/roberts/alpha.ps
(The vertical axis is $\alpha_S$ over $\pi$;
the horizontal axis is log base 10 of $Q$.)

As you'll recall we found differences between the
PDFs resulting from the CTEQ and MRST evolution codes
(with the same input PDFs at 1 GeV) at small $x$ and
intermediate $Q$.  Perhaps the differences in $\alpha_S$
can explain the differences in evolved PDFs.
More likely, the same kinds of differing choices that
produce different values of $\alpha_{S}$ also produce
differences in the evolution of PDFs.  For example,
the treatment of the charm threshold may affect both
quantities.

Best regards,
Dan Stump