| bcdalloc {SeqAlloc} | R Documentation |
Biased Coin Design Allocation
Description
Allocates observations sequentially using a biased coin design. If equal numbers have been allocated to treatment and control, the next observation is allocated to treatment with probability 1/2. If there are more units assigned to treatment than control, the next observation is allocated to control with probability p; if there are more units assigned to control than treatment, the next observation is allocated to treatment with probability p.
Usage
bcdalloc(n, pbcd, tol = 1e-06)
Arguments
n |
number of observations |
pbcd |
probability p used for biased coin |
tol |
tolerance used for allocation |
Value
Vector of zeroes and ones indicating the allocation of each unit to treatment (1) or control (0)
Author(s)
Xiaoshu Zhu xiaoshuzhu@westat.com and Sharon Lohr
References
Efron, B. (1971). Forcing a sequential experiment to be balanced. Biometrika, 58(3), 403-417.
Lohr, S. and X. Zhu (2015). Randomized Sequential Individual Assignment in Social Experiments: Evaluating the Design Options Prospectively. Sociological Methods and Research. [Advance online publication: December 27, 2015] doi: 10.1177/0049124115621332.
Examples
bcdalloc(20,0.7)