  Gamow-Teller strength functions in full $(pf)^{8}$ spaces are calculated with
sufficient accuracy to ensure that all the states in the resonance region have
been populated. Many of the resulting peaks are weak enough to become
unobservable. The quenching factor necessary to bring into agreement the low
lying observed states with shell model predictions is shown to be due to
nuclear correlations. To within experimental uncertainties it is the same that
is found in one particle transfer and (e,e') reactions. Perfect consistency
between the observed $^{48}Ca(p,n)^{48}Sc$ peaks and the calculation is
achieved by assuming an observation threshold of 0.75\% of the total strength,
a value that seems typical in several experiments
