mc.add.to.design: Add cards to a design

In MConjoint: Conjoint Analysis through Averaging of Multiple Analyses

Description

Given a "good" design add some cards to get a new design

Usage

mc.add.to.design(all.possible, old.design, cards.to.add = 3, slack = 1, 
                 tol = 0.2, max.trials = 100, max.good.designs=100)

mc.add.to.design.fast(all.possible, old.design, cards.to.add = 3, slack = 1, tol = 0.2)

Arguments

all.possible	all possible cards (can be all combinations of factors, or some can be removed)
old.design	An initial "good" design
cards.to.add	the number of cards to add
slack	How much the number of each factor can vary in a "good" design
tol	The largest cross correlation in a "good" design
max.trials	The maximum number of samples of extra.cards cards to look at.
max.good.designs	For any trial design, the maximum number of good designs to look for

Details

The function will take samples of size extra.cards from the set of cards all.possible-old.design and add them to old.design. For each sample the number of "good" (balanced an low cross correlation) designs of the same size as old.design is found. The sample which gives the largest number of "good" designs is used.

The default max.trials of 100 will lead to run times of several hours for largish problems. You can usually decrease this without losing too much. Increasing the number of trials may increase the number of good designs found, but usually not by much.

The default max.good.designs is set to 100. Analyzing more than this number of designs is unlikely to be needed outside of theoretical work.

mc.add.to.design.fast is useful for quick and dirty work

Value

base.design	The original old.design
added	The sample of cards added
design	The combined set of cards randomized

Author(s)

William Hughes

Examples

data(hire.candidates)
base.design = mc.get.one.design(hire.candidates, 9)

#use defaults, (except max.trials=10 for speed)

mc.add.to.design(hire.candidates,base.design, max.trials=10)

#add 4 cards, accepting cross corellations up to .35
#warning, this may take several minutes

#mc.add.to.design(hire.candidates,base.design,4,tol=.35)

# you can speed this up and in this case
# have almost as many good designs (53 vs.54)

#mc.add.to.design(hire.candidates,base.design,4,tol=.35,max.trials=10)

MConjoint documentation built on May 1, 2019, 7:56 p.m.