How to Use This Tool
Allocate participant IDs across arms inside blocks while preserving exact counts and audit order. Generate deterministic blocked experiment assignments from IDs, block labels, treatment ratios and a visible seed, then export an auditable CSV plan.
The work this page finishes
Assignments made ad hoc can drift from the declared ratio or become impossible to reproduce, especially when separate sites or cohorts must remain balanced. For Randomization Plan, the row-preserving workspace makes a correction repeatable without rebuilding a prompt or transmitting the source file.
Deterministic workflow
Validate unique participant IDs and weighted arms, group by the supplied block, sort each block with a visible seeded hash and cycle through the declared allocation ratio. For Randomization Plan, this page accepts at most 5,000 records and 2 MB of text; rejected items retain their row references while valid items remain available.
Why a dedicated interface helps
Freeze the exported plan before enrollment or analysis and have the study owner review concealment, ethics, power and the approved randomization procedure. For Randomization Plan, immediate recalculation and a stable export are useful when the same rule must be applied consistently across a list instead of explained one item at a time.
Assumptions
- Participant IDs are non-sensitive test or approved identifiers.
- Blocks are declared before assignment.
- Weights describe the intended within-block cycle.
For Randomization Plan, retain the original source until the destination accepts the result; processing stays in this tab, although the device and installed extensions remain part of the user's security boundary.
Limitations and review boundary
This is planning software, not a clinical randomization service; it is not cryptographically unpredictable and does not provide allocation concealment, power analysis or regulatory compliance. For Randomization Plan, no supplied URL is requested and no pasted markup or code is executed; output is inserted through text-only DOM operations.
Verification and provenance
The implementation was checked against NIST/SEMATECH e-Handbook — Randomization on 2026-08-26, with fixtures for a known answer, an invalid input and a batch-specific edge condition. The sample assigns six IDs within two site blocks to control and treatment using a reproducible 1:1 cycle and seed 42.
Sources & assumptions
Tool Spec v2 · verified 2026-08-26. Platform rules and fees can change; the editable inputs remain authoritative for your account.
Official references
- NIST/SEMATECH e-Handbook — Randomization (checked 2026-08-26)
Model assumptions
- Participant IDs are non-sensitive test or approved identifiers.
- Blocks are declared before assignment.
- Weights describe the intended within-block cycle.
- This is planning software, not a clinical randomization service; it is not cryptographically unpredictable and does not provide allocation concealment, power analysis or regulatory compliance.
