randomizeR: abcdPar – R documentation

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randomizeR

abcdPar

Representing Accelerated Biased Coin Design

Description

Represents the randomization procedure Accelerated Biased Coin Design.

Usage

abcdPar(N, a, groups = LETTERS[1:2])

Arguments

`N`	integer for the total sample size of the trial.
`a`	nonnegative parameter which controls the degree of randomness: For decreasing `a` the allocations become deterministic, while for increasing `a` the randomization procedure tends to complete randomization.
`groups`	character vector of labels for the different treatments.

Details

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.

Value

S4 object of the class abcdPar.

References

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