  A new analysis of hyperon semi-leptonic decay data is presented, based on
simple and general arguments for an SU(3)-breaking structure of the couplings
involved. The results obtained are compatible with those of earlier
investigations and highlight the uncertainties inherent in extraction of the
V_us Cabibbo-Kobayashi-Maskawa matrix element from such data, and the need for
complete analyses. For F and D, the results can be summarised by the ratio:
F/D=0.57+/-0.01; while as far as the value of V_us is concerned, the only
conclusion to be drawn is that, insofar as SU(3) breaking is still not totally
under control, the value obtained is compatible but not competitive with that
obtained from kaon semi-leptonic decays.
