The sparsity-of-effects principle
states that a system is usually dominated by main effects and low-order interactions. Thus it is most likely that main (single factor) effects and two-factor interactions are the most significant responses (see factorial experiment
). In other words, higher order interactions such as three-factor interactions are very rare. Formally, Wu and Hamada (2000, page 112) refer to this as the hierarchical ordering principle
. They state that the effect sparsity principle
actually refers to the idea that only a few effects in a factorial experiment will be statistically significant.
- Wu, C. F. Jeff and Hamada, Michael (2000) Experiments: Planning, analysis, and parameter design optimization, New York: Wiley, ISBN 0-471-25511-4.