Represents the randomization procedure Accelerated Biased Coin Design.
abcdPar(N, a, groups = LETTERS[1:2])integer for the total sample size of the trial.
nonnegative parameter which my be adjusted according to how strongly it is
desired to balance the experiment. a = 0 gives the complete randomization, while the
assignments become more deterministic as a increases.
character vector of labels for the different treatments.
S4 object of the class abcdPar.
This is a class of 'biased coins' where the probability of selecting the under-represented treatment is dependent from the absolute difference between the two treatment allocations up to the current step.
A. B. Antognini and A. Giovagnoli (2004) A new 'biased coin design' for the sequential allocation of two treatments. Journal of the Royal Statistical Society. Series C (Applied Statistics) 53, No. 4, 651-664
Other randomization procedures: bbcdPar,
bsdPar, chenPar,
crPar, createParam,
ebcPar, gbcdPar,
hadaPar, mpPar,
pbrPar, rarPar,
rpbrPar, rtbdPar,
tbdPar, udPar