  Two partial orderings among communication channels, namely, `being degradable
into' and `being less noisy than,' are reconsidered in the light of recent
results about statistical comparisons of quantum channels. Though our analysis
covers at once both classical and quantum channels, we also provide a separate
treatment of classical noisy channels, and show how, in this case, an
alternative self-contained proof can be constructed, with its own particular
merits with respect to the general result.
