Randomization Generator

Randomization is the process of assigning subjects to treatment groups by chance to eliminate selection bias and ensure comparability of groups. It's the cornerstone of experimental design.

• Simple Random: Each subject has equal probability of assignment. Simple but may result in imbalanced groups, especially with small samples.
• Block Randomization: Subjects are allocated in blocks to ensure balance throughout enrollment. Block size determines how many subjects are randomized together.
• Stratified Randomization: Separate randomization within subgroups defined by important baseline characteristics (strata) to ensure balance on those factors.

Not all studies use 1:1 allocation. Common alternatives:

• 2:1 ratio: Two subjects to new treatment for every one to control. Useful when learning about safety/efficacy of new treatment.
• 3:1 ratio: Maximum information about new treatment while maintaining control group.
• Equal allocation (1:1): Provides maximum statistical power for given sample size.

• Clinical trials with treatment and control groups
• A/B testing with multiple variants
• Educational interventions comparing teaching methods
• Agricultural field trials
• Psychology experiments with random assignment