Evidence-appraisal glossary
Random Sequence Generation
The step of creating the unpredictable order in which participants will be assigned to trial groups, for example with a computer random number generator. Doing it soundly is the foundation of randomization; concealing it is a separate safeguard.
Also called: sequence generation, allocation sequence.
A proper sequence is genuinely random, so that neither a patient's prognosis nor an investigator's wishes can shape who lands in which arm. Methods that look random but are not, such as alternating patients or assigning by day of the week, are predictable and open the door to selection bias. Sequence generation answers how the order was made, while allocation concealment answers whether anyone could see it coming.
Read the full Reading the Evidence blog.
This is a plain-language methodology definition for reading research. It is general education, not medical advice.