Alternatively known as Successive Approximation Character Weighting (SACW) This is a method of reweighting characters based on some measure of their relative values for the purposes of phylogeny reconstruction If, for instance, an initial analysis is carried out and the result of this analysis indicates that some characters are quite inconsistent with the resulting tree(s), then these will be down-weighted in subsequent analyses The index for downweighting the characters might be the retention index, consistency index or some such measure of consistency of a character with a tree Iterative analyses are carried out, with the individual characters being reweighted each time until there is little or no change in the resulting topology
The procedure used in shaping a behavior The subject is reinforced for successively closer approximations to the desired behavior until that behavior is emitted
The iterative scheme by which an approximation is used for the basic design of an algorithm The sequence generated is of the form x^(k+1) = x^k + A(x^k), where A is an algorithm map specified by its approximation to some underlying goal Typically, this is used to find a fixed point, where A(x)=0 (e g , seeking f(x)=x, let A(x) = f(x) - x, so the iterations are x^(k+1) = f(x^k), converging to x*=f(x*) if f satisfies certain conditions, such as a contraction map)