Randomization Settings

To access Randomization Settings, you must select a study from the landing page after clicking on the Randomization module. Randomization Settings allow you to choose a Randomization Type, format a Randomization ID, provide and access Kit information, and record Treatments.

Note that when selecting the From Subject ID Randomization ID Formatting type, the Subject ID must be unique for each Study.

Study Settings

In the Study Settings section, you can choose how you would like to Randomize (by Study or by Site), the type of Randomization that will be used, whether or not to allow Unbalanced Randomization, whether or not to Mask the treatment data, which email group will receive an email notification when data is unmasked, and whether or not Sites will be required to enter login credentials before revealing treatment.

Randomization Types

Before selecting a Randomization type, you must configure Randomization settings. A Randomization List Template will be generated based on what type of Randomization is chosen. This template will be accessible in the Randomization Lists tab. The types of Randomization used in the Randomization module are detailed below.

Simple Randomization

As subjects are randomized, each new subject takes the next record sequentially available in the Randomization record.


When using blocks, a randomized list is organized into blocks and subjects are divided into smaller groups. The subjects in each group are then randomly assigned to a block. That block must be filled before the next block can be assigned subjects.


In Stratification, subjects are separated by strata into groups that are defined by that strata, such as Sex or Age, to assign treatment of equal numbers to subjects with similar characteristics.

Stratification with Blocks

Stratification with blocks is a combination of stratification and blocking in that subjects are divided into small groups but further classified by proposed strata.

Mixed Blocks

A Randomization list is organized into blocks that are typically different sizes (eg. blocks of 4 and blocks of 6). This Randomization Type is supported by selecting “Blocks” and “Unbalanced Randomization.”

Dynamic Site Assignment

Vault will dynamically assign sites to subjects as they are randomized based on selected configuration, which is called Dynamic Site Assignment. Dynamic Site Assignment occurs when you’re randomizing by Site and your Randomization Type is either Blocks or Stratification with Blocks.