  We study decimation procedures and effective (improved) actions in the
framework of Monte Carlo Renormalization Group (MCRG). Particular attention is
paid to matching the form of the effective action to the decimation procedure
parameters. Using the static quark-antiquark potential in SU(2) LGT we probe
different distance scales and find that an effective action containing multiple
group representations is capable of reproducing long distance physics well. In
particular, appropriate matching results in the practical elimination of the
coarsening/fining effect of the lattice spacing under decimation. The short
distance regime of the effective theory is also studied. We next carry out
studies of effective actions involving both multiple representations and loops
beyond the single plaquette towards determining an improved action good over a
wide length scale regime.
