  I carry out a finite-size scaling study of the correlation length in SU(3)
lattice gauge theory coupled to 12 fundamental flavor fermions, using recent
data published by Fodor, Holland, Kuti, Nogradi and Schroeder. I make the
assumption that the system is conformal in the zero-mass, infinite volume
limit, that scaling is violated by both nonzero fermion mass and by finite
volume, and that the scaling function in each channel is determined
self-consistently by the data. From several different observables I extract a
common exponent for the scaling of the correlation length xi with the fermion
mass m_q, xi proportional to m_q to the power -1/y_m, with y_m ~ 1.35.
Shortcomings of the analysis are discussed.
