study design Plackett-Burman design Alejandra Gonzalez-Beltran Orlaith Burke Philippe Rocca-Serra Plackett-Burman design is a type of study design optimizing multifactorial experiments characterized by their parsimony and economy with the run number a multiple of 4 (rather than a power of 2). Plackett-Burman design is often used for screening experiments where the main effect is often heavily confounded with two-factor interactions. This type of design is very useful for economically detecting large main effects, assuming all interactions are negligible when compared with the few important main effects. http://www.itl.nist.gov/div898/handbook/pri/section3/pri335.htm pb(nruns, nfactors = nruns - 1, factor.names = if (nfactors <= 50) Letters[1:nfactors] else paste("F", 1:nfactors, sep = ""), default.levels = c(-1, 1), ncenter=0, center.distribute=NULL, boxtyssedal = TRUE, n12.taguchi = FALSE, replications = 1, repeat.only = FALSE, randomize = TRUE, seed = NULL, oldver = FALSE, ...) from: http://www.inside-r.org/packages/cran/FrF2/docs/pb pending final vetting