Full Idea
If multiple realisability means that psychological terms cannot be translated into physics, one weaker kind of reductionism resorts to 'bridge laws' which link the theory to be reduced to the reducing theory.
Gist of Idea
A weaker kind of reductionism than direct translation is the use of 'bridge laws'
Source
Robert Kirk (Mind and Body [2003], §3.8)
Book Reference
Kirk,Robert: 'Mind and Body' [Acumen 2003], p.61
A Reaction
It seems to me that reduction is all-or-nothing, so there can't be a 'weaker' kind. If they are totally separate but linked by naturally necessary laws (e.g. low temperature and ice), they are supervenient, but not reducible to one another.