Contents - Index
A selection Index is a linear combination of a set of traits. Each trait is given a weight between [-1, +1] based on its direction of action (higher levels are favorable or unfavorable) and importance, as judged by the researcher.
Since the selection index is a linear combination of the traits, it has two major properties:
1) it allows multiple traits are selected on the same time, and
2) it allows the trait to compensate for each other such that a genotype may be selected if it has a large Selection Index even though it has obvious defects on some traits.
More: Selection based on multiple traits.