One more than the smallest nth-order interaction effect that some main effect is aliased with.
Notes: - Resolution is used to describe the extent to which fractional-factorial designs create aliased effects.
- The resolution is written as a Roman numeral.
- Full-factorial designs have no effects that are aliased and therefore have infinite resolution.
Example: For resolution III designs the main effects are aliased with two-factor interactions. For resolution IV designs no main effects are aliased with two-factor interactions, but two-factor interactions are aliased with each other. For resolution V designs no main effect or two-factor interaction is aliased with any other main effect or two-factor interaction, but two-factor interactions are aliased with three-factor interactions.
Source:
PAC, 2016, 88, 407. 'Vocabulary of concepts and terms in chemometrics (IUPAC Recommendations 2016)' on page 417 (https://doi.org/10.1515/pac-2015-0605)