Random Allocation to Two Independent Groups


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This function allocates a given number of subjects at random to one of two independent groups.


Randomization reduces opportunities for bias and confounding in experimental designs, and leads to treatment groups which are random samples of the population sampled, thus helping to meet assumptions of subsequent statistical analysis (Bland, 2000).


Two independent groups might be intervention and control groups, for example to examine the effect of a new treatment. For a randomized controlled trial of a new treatment you would randomly allocate some subjects to receive the new treatment and the other subjects to receive the control treatment (e.g. placebo drug). For a total of 30 subjects in two groups of 15 you would enter 30 into this function:


Unpaired random allocation to intervention or control group

Randomized with seed: 10

Intervention 1 Control 2
Intervention 3 Control 6
Intervention 4 Control 8
Intervention 5 Control 12
Intervention 7 Control 13
Intervention 9 Control 16
Intervention 10 Control 17
Intervention 11 Control 20
Intervention 14 Control 21
Intervention 15 Control 23
Intervention 18 Control 24
Intervention 19 Control 25
Intervention 22 Control 27
Intervention 26 Control 28
Intervention 30 Control 29


- here the first subject would be allocated to the control group and the second to the treatment group etc.


Technical validation

Robust (pseudo-)random number generation is used, see random number generation.



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