THECONCEPTOFDESIGNRESOLUTION:

REACTOREXAMPLE

The2^5-1fractionis calledaresolutionVdesign.Lookingattheconfounding patternwe seethat1₁[!]1 + 2345and1₁₂[!]12+ 345.Thus maineffects areconfoundedwith four-factor interactions, andtwo- factor interactions withthree-factor interactions.

Ingeneral,a design ofresolutionR is oneinwhichnop-factor effectis confoundedwithany other effect

containing less thanR-pfactors.

Theresolutionofadesignis denotedby theappropriate Roman letter

appendedas asubscript.

To illustrate:

1.

A designofresolution R = IIIdoes notconfound maineffects withoneanother butdoes confoundmaineffects withtwo-factor interactions.

A designofresolution R = IV does not confoundmaineffects andtwo-factorinteractions but does confound two-factorinteractions withothertwo-factorinteractions.

A designofresolution R = V does notconfoundmain effects andtwo-factorinteractions with eachother,butdoes confoundtwo-factor interactions with three-factorinteractions,and soon.

2.

3.

Ingeneral,theresolution ofatwo-level fractional designisthelengthof theshortest wordin thedefining relation.