Fractional Factorial Analysis Objects

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DESCRIPTION:

Classes of objects that result from the analysis of fractional factorial designs.

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GENERATION:

These classes of objects are returned from fac.aov. An object of class "fac.aov" represents the fit for a fractional factorial analysis of variance.

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METHODS:

The class "fac.aov" has methods for the following generic functions: pareto, plot, predict, print, print.summary, qqnorm, summary.

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INHERITANCE:

Class "fac.aov" inherits from class "aov".

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STRUCTURE:

The fac.aov object is implemented as a list with the following components in addition to an aov object:

fcoefficients:

The fractional factorial coefficients give the parametrization of a convential fit for factorial experiments, i.e. 1/2 of the average difference between high and low levels of the factor. These are sometimes referred to as half-effects.

feffects:

For a standard fractional factorial design, these are the conventional effects (twice the fcoefficients or half-effects). For unbalanced or nonorthogonal designs, the feffects are calculated from the fcoefficients using the value of adj.coef to make all of the standard errors equal. (See below.)

seffects:

The effects from the saturated model. In most cases these are identical to feffects. However if a fac.aov object has been refitted with update, forming a non-saturated model, the saturated effects are stored here, and the reduced model effects in feffects

adj.coef:

A vector of adjustment factors used in feffects = fcoefficients*adj.coef so that feffects have a constant standard error, a property that is required for the computation methods used for pse, tse and ase.

mse:

error estimates corresponding to the mean square standard error.

pse:

error estimates corresponding to the pseudo standard error.

tse:

error estimates corresponding to the trimmed standard error.

ase:

error estimates corresponding to the adaptive standard error.

design.name:

The design name, if any, from the original data.

x:

the model matrix created by the call to aov.

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SEE ALSO:

update , fac.design , fac.aov , pse , tse , ase .